diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query1.sqlpp
index 71c910f..9e24961 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query2.sqlpp
index 2d7e3a0..bdc0089 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query2.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-1/query2.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string) ;
 
 SELECT COUNT(*)
 FROM YelpCheckin C, C.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query1.sqlpp
index c0f0377..2a8e0ba 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_times.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query2.sqlpp
index e624637..6eaeb8b 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query2.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-2/query2.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string) ;
 
 SELECT COUNT(*)
 FROM YelpCheckin C, C.checkin_times.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query1.sqlpp
index 7054aed..ff8aaf2 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ? ) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_times D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query2.sqlpp
index ecfd0c5..cf4dbe7 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query2.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query2.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string) ;
 
 SELECT COUNT(*)
 FROM YelpCheckin C, C.checkin_times D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query3.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query3.sqlpp
index 97506d7..e2bc739 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query3.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-3/query3.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ? ) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_times D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query1.sqlpp
index 464705e..4037a3b 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_times CT, CT.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query2.sqlpp
index 26fd6e8..0435f33 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query2.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/use-case-4/query2.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string) ;
 
 SELECT COUNT(*)
 FROM YelpCheckin C, C.checkin_times CT, CT.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query1.sqlpp
index 913d010..2855490 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string) ;
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_data.checkin_temporal.checkin_times.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query2.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query2.sqlpp
index 8d56541..fb0bc10 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query2.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-3-level-record-path/query2.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string) ;
 
 SELECT COUNT(*)
 FROM YelpCheckin C, C.checkin_data.checkin_temporal.checkin_times.dates D
diff --git a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-composite-sk/query1.sqlpp b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-composite-sk/query1.sqlpp
index 3dcc3a2..37ef7a7 100644
--- a/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-composite-sk/query1.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/optimizerts/queries/array-index/select-unnest-queries/open/with-composite-sk/query1.sqlpp
@@ -27,7 +27,7 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDatesTimes ON YelpCheckin (UNNEST checkin_times SELECT date : string ?, time : string ?);
+CREATE INDEX IdxYelpCheckinDatesTimes ON YelpCheckin (UNNEST checkin_times SELECT date : string , time : string);
 
 SELECT C.business_id
 FROM YelpCheckin C, C.checkin_times D
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/after-index-creation/with-open-index/with-open-index.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/after-index-creation/with-open-index/with-open-index.1.ddl.sqlpp
index 95d4be1..aa3a456 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/after-index-creation/with-open-index/with-open-index.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/after-index-creation/with-open-index/with-open-index.1.ddl.sqlpp
@@ -30,4 +30,4 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-1/use-case-1.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-1/use-case-1.3.ddl.sqlpp
index b933d8a..0d37224 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-1/use-case-1.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-1/use-case-1.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-2/use-case-2.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-2/use-case-2.3.ddl.sqlpp
index 51a1c82..abacfe8 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-2/use-case-2.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-2/use-case-2.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.3.ddl.sqlpp
index aa50e82..9594cf9 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.5.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.5.ddl.sqlpp
index 408a465..982affc 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.5.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-3/use-case-3.5.ddl.sqlpp
@@ -20,4 +20,4 @@
 USE TestYelp;
 
 DROP INDEX YelpCheckin.IdxYelpCheckinDates;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?, time : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string , time : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-4/use-case-4.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-4/use-case-4.3.ddl.sqlpp
index b349a8a..c590ecb 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-4/use-case-4.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/bulk-loading/on-index-creation/open/use-case-4/use-case-4.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-on-closed-array/index-on-closed-array.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-on-closed-array/index-on-closed-array.1.ddl.sqlpp
index 65cdcfe..685485b 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-on-closed-array/index-on-closed-array.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-on-closed-array/index-on-closed-array.1.ddl.sqlpp
@@ -35,5 +35,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string?);
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string);
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-with-enforced-type/index-with-enforced-type.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-with-enforced-type/index-with-enforced-type.1.ddl.sqlpp
index 45ecfbe..baf5bc0 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-with-enforced-type/index-with-enforced-type.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/error-handling/index-with-enforced-type/index-with-enforced-type.1.ddl.sqlpp
@@ -35,5 +35,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string?) ENFORCED;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string) ENFORCED;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-1/use-case-1.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-1/use-case-1.1.ddl.sqlpp
index 0e54946..ab374bf 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-1/use-case-1.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-1/use-case-1.1.ddl.sqlpp
@@ -33,4 +33,4 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY business_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-2/use-case-2.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-2/use-case-2.1.ddl.sqlpp
index 9b0d495..ef8d1c2 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-2/use-case-2.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-2/use-case-2.1.ddl.sqlpp
@@ -33,5 +33,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY business_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
-CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times.times : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ) ;
+CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times.times : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-3/use-case-3.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-3/use-case-3.1.ddl.sqlpp
index 1d44ffb..768692b 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-3/use-case-3.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-3/use-case-3.1.ddl.sqlpp
@@ -33,5 +33,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY business_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?) ;
-CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times SELECT time : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ) ;
+CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times SELECT time : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-4/use-case-4.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-4/use-case-4.1.ddl.sqlpp
index 4b8453f..068482f 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-4/use-case-4.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/use-case-4/use-case-4.1.ddl.sqlpp
@@ -33,5 +33,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY business_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
-CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times UNNEST times : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ) ;
+CREATE INDEX IdxYelpCheckinTimes ON YelpCheckin (UNNEST checkin_times UNNEST times : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-additional-atomic-index/with-additional-atomic-index.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-additional-atomic-index/with-additional-atomic-index.1.ddl.sqlpp
index 5edd2a0..cc59e2f 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-additional-atomic-index/with-additional-atomic-index.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-additional-atomic-index/with-additional-atomic-index.1.ddl.sqlpp
@@ -33,5 +33,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
 CREATE INDEX IdxYelpCheckinBusinessID ON YelpCheckin (business_id : string ?) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-composite-sk/with-composite-sk.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-composite-sk/with-composite-sk.1.ddl.sqlpp
index 9046654..da9eb7ea 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-composite-sk/with-composite-sk.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/insert-upsert-delete/open/with-composite-sk/with-composite-sk.1.ddl.sqlpp
@@ -33,4 +33,4 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?, time : string ?);
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string , time : string );
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/join-unnest-queries/with-open-index/with-open-index.4.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/join-unnest-queries/with-open-index/with-open-index.4.ddl.sqlpp
index b933d8a..0d37224 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/join-unnest-queries/with-open-index/with-open-index.4.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/join-unnest-queries/with-open-index/with-open-index.4.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-1/use-case-1.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-1/use-case-1.1.ddl.sqlpp
index b52f35a..62d70c3 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-1/use-case-1.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-1/use-case-1.1.ddl.sqlpp
@@ -31,5 +31,5 @@
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
 CREATE INDEX IdxYelpCheckinBusinessID ON YelpCheckin (business_id : string?) ;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates: string?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates: string) ;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-2/use-case-2.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-2/use-case-2.1.ddl.sqlpp
index 8881b4d..0edb2cb 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-2/use-case-2.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-2/use-case-2.1.ddl.sqlpp
@@ -31,5 +31,5 @@
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
 CREATE INDEX IdxYelpCheckinBusinessID ON YelpCheckin (business_id : string?) ;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ) ;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-3/use-case-3.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-3/use-case-3.1.ddl.sqlpp
index 5839c9b..733d2d9 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-3/use-case-3.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-3/use-case-3.1.ddl.sqlpp
@@ -31,5 +31,5 @@
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
 CREATE INDEX IdxYelpCheckinBusinessID ON YelpCheckin (business_id : string ?) ;
-CREATE INDEX IdxYelpCheckinDate ON YelpCheckin (UNNEST checkin_times SELECT date : string ?) ;
-CREATE INDEX IdxYelpCheckinTime ON YelpCheckin (UNNEST checkin_times SELECT time : string ?) ;
+CREATE INDEX IdxYelpCheckinDate ON YelpCheckin (UNNEST checkin_times SELECT date : string ) ;
+CREATE INDEX IdxYelpCheckinTime ON YelpCheckin (UNNEST checkin_times SELECT time : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-4/use-case-4.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-4/use-case-4.1.ddl.sqlpp
index ad01847..8ea3bfe 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-4/use-case-4.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/use-case-4/use-case-4.1.ddl.sqlpp
@@ -31,5 +31,5 @@
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
 CREATE INDEX IdxYelpCheckinBusinessID ON YelpCheckin (business_id : string?) ;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ) ;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-3-level-record-path/with-3-level-record-path.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-3-level-record-path/with-3-level-record-path.1.ddl.sqlpp
index 4a21b30..c9b993c 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-3-level-record-path/with-3-level-record-path.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-3-level-record-path/with-3-level-record-path.1.ddl.sqlpp
@@ -30,5 +30,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ) ;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-composite-array-different-indicators/with-composite-array-different-indicators.1.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-composite-array-different-indicators/with-composite-array-different-indicators.1.ddl.sqlpp
index c3a181a..5747a3c 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-composite-array-different-indicators/with-composite-array-different-indicators.1.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/metadata/open/with-composite-array-different-indicators/with-composite-array-different-indicators.1.ddl.sqlpp
@@ -30,5 +30,5 @@
 };
 
 CREATE DATASET YelpCheckin(CheckinType) PRIMARY KEY checkin_id AUTOGENERATED;
-CREATE INDEX IdxYelpCheckinDateTime ON YelpCheckin (UNNEST checkin_times SELECT date : string ?, t.time : string ?) ;
+CREATE INDEX IdxYelpCheckinDateTime ON YelpCheckin (UNNEST checkin_times SELECT date : string , t.time : string ) ;
 
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-quantified-queries/with-open-index/with-open-index.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-quantified-queries/with-open-index/with-open-index.3.ddl.sqlpp
index b933d8a..0d37224 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-quantified-queries/with-open-index/with-open-index.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-quantified-queries/with-open-index/with-open-index.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-1/use-case-1.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-1/use-case-1.3.ddl.sqlpp
index b933d8a..0d37224 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-1/use-case-1.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-1/use-case-1.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-2/use-case-2.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-2/use-case-2.3.ddl.sqlpp
index 51a1c82..abacfe8 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-2/use-case-2.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-2/use-case-2.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times.dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-3/use-case-3.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-3/use-case-3.3.ddl.sqlpp
index aa50e82..9594cf9 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-3/use-case-3.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-3/use-case-3.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times SELECT date : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-4/use-case-4.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-4/use-case-4.3.ddl.sqlpp
index b349a8a..c590ecb 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-4/use-case-4.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/use-case-4/use-case-4.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_times UNNEST dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-3-level-record-path/with-3-level-record-path.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-3-level-record-path/with-3-level-record-path.3.ddl.sqlpp
index 599552a..88a6782 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-3-level-record-path/with-3-level-record-path.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-3-level-record-path/with-3-level-record-path.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ?) ;
+CREATE INDEX IdxYelpCheckinDates ON YelpCheckin (UNNEST checkin_data.checkin_temporal.checkin_times.dates : string ) ;
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-composite-sk/with-composite-sk.3.ddl.sqlpp b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-composite-sk/with-composite-sk.3.ddl.sqlpp
index ab9a6f8..a8cf7d4 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-composite-sk/with-composite-sk.3.ddl.sqlpp
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/queries_sqlpp/array-index/select-unnest-queries/open/with-composite-sk/with-composite-sk.3.ddl.sqlpp
@@ -19,4 +19,4 @@
 
 USE TestYelp;
 
-CREATE INDEX IdxYelpCheckinDatesTimesBusiness ON YelpCheckin (UNNEST checkin_times SELECT date : string ?, time : string ?);
+CREATE INDEX IdxYelpCheckinDatesTimesBusiness ON YelpCheckin (UNNEST checkin_times SELECT date : string , time : string );
diff --git a/asterixdb/asterix-doc/src/main/grammar/sqlpp.ebnf b/asterixdb/asterix-doc/src/main/grammar/sqlpp.ebnf
index 1fec807..db89fe0 100644
--- a/asterixdb/asterix-doc/src/main/grammar/sqlpp.ebnf
+++ b/asterixdb/asterix-doc/src/main/grammar/sqlpp.ebnf
@@ -218,7 +218,8 @@
                | IndexField
                | "(" ( ArrayIndexElement | IndexField ) ")"
 
-ArrayIndexElement ::= "UNNEST" NestedField ( "UNNEST" NestedField )* ( ( ":" TypeReference "?"? ) | ( "SELECT" IndexField ( "," IndexField )* ) )?
+ArrayIndexElement ::= "UNNEST" NestedField ( "UNNEST" NestedField )*
+                      ( ( ":" TypeReference ) | ( "SELECT" NestedField ( ":" TypeReference )? ( "," NestedField ( ":" TypeReference )? )* ) )?
 
 IndexField ::= NestedField ( ":" TypeReference "?"? )?
 
diff --git a/asterixdb/asterix-doc/src/site/markdown/sqlpp/arrayindex.md b/asterixdb/asterix-doc/src/site/markdown/sqlpp/arrayindex.md
index 5841e67..559e2d2 100644
--- a/asterixdb/asterix-doc/src/site/markdown/sqlpp/arrayindex.md
+++ b/asterixdb/asterix-doc/src/site/markdown/sqlpp/arrayindex.md
@@ -155,9 +155,9 @@
 Similar to atomic indexes, array indexes are not limited to closed fields.
 The following DDLs illustrate how we could express `CREATE INDEX` statements comparable to those above if the to-be-indexed fields were not included in the their dataset's type definitions.
 
-    CREATE INDEX pCategoriesIdx ON products (UNNEST categories : string?);
-    CREATE INDEX oItemsQtyPriceIdx ON orders (UNNEST items SELECT qty : int?, price : int?);
-    CREATE INDEX oProductIDIdx ON orders (UNNEST items SELECT productno : int?);
+    CREATE INDEX pCategoriesIdx ON products (UNNEST categories : string);
+    CREATE INDEX oItemsQtyPriceIdx ON orders (UNNEST items SELECT qty : int, price : int);
+    CREATE INDEX oProductIDIdx ON orders (UNNEST items SELECT productno : int);
 
 ### Arrays in Arrays
 
diff --git a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
index 4dac902..e1db7b7 100644
--- a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
+++ b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
@@ -1190,21 +1190,27 @@
   List<String> path = null;
   IndexedTypeExpression type = null;
   List<List<String>> unnestList = new ArrayList();
-  Pair<List<String>, IndexedTypeExpression> field = null;
   List<Pair<List<String>, IndexedTypeExpression>> projectList = new ArrayList();
 }
 {
   path = MultipartIdentifier() { unnestList.add(path); }
   ( <UNNEST> path = MultipartIdentifier() { unnestList.add(path); })*
   (
-    ( <COLON> type = IndexedTypeExpr()
+    ( <COLON> type = IndexedTypeExpr(false)
       {
         projectList.add(new Pair<List<String>, IndexedTypeExpression>(null, type));
       }
     ) |
     (
-      <SELECT> field = IndexedField() { projectList.add(field); }
-      ( <COMMA> field = IndexedField() { projectList.add(field); } )*
+      <SELECT> path = MultipartIdentifier() ( <COLON> type = IndexedTypeExpr(false) )?
+      {
+        projectList.add(new Pair<List<String>, IndexedTypeExpression>(path, type));
+      }
+      ( <COMMA> path = MultipartIdentifier() ( <COLON> type = IndexedTypeExpr(false) )?
+        {
+          projectList.add(new Pair<List<String>, IndexedTypeExpression>(path, type));
+        }
+      )*
     )
   )?
   {
@@ -1223,7 +1229,7 @@
   IndexedTypeExpression type = null;
 }
 {
-  path = MultipartIdentifier() ( <COLON> type = IndexedTypeExpr() )?
+  path = MultipartIdentifier() ( <COLON> type = IndexedTypeExpr(true) )?
   {
     return new Pair<List<String>, IndexedTypeExpression>(path, type);
   }
@@ -2523,14 +2529,21 @@
     }
 }
 
-IndexedTypeExpression IndexedTypeExpr() throws ParseException:
+IndexedTypeExpression IndexedTypeExpr(boolean allowQues) throws ParseException:
 {
   TypeExpression typeExpr = null;
-  boolean isUnknownable = false;
+  boolean isUnknownable = !allowQues;
 }
 {
   typeExpr = TypeExpr(false)
-  ( <QUES> { isUnknownable = true; } )?
+  ( <QUES>
+    {
+      if (!allowQues) {
+        throw new SqlppParseException(getSourceLocation(token), "'?' quantifier is illegal for the type expression.");
+      }
+      isUnknownable = true;
+    }
+  )?
   {
     return new IndexedTypeExpression(typeExpr, isUnknownable);
   }
@@ -2770,7 +2783,7 @@
 }
 {
   fieldList = NestedField()
-  ( <COLON> fieldType = IndexedTypeExpr() )?
+  ( <COLON> fieldType = IndexedTypeExpr(true) )?
   {
     return new Pair<Integer, Pair<List<String>, IndexedTypeExpression>>
             (fieldList.first, new Pair<List<String>, IndexedTypeExpression>(fieldList.second, fieldType));