commit fdedf6263cca9bb87a2baf0eccb7864a26c8aaf9
author Dmitry Lychagin <dmitry.lychagin@couchbase.com> Tue Oct 30 18:12:40 2018 -0700
committer Dmitry Lychagin <dmitry.lychagin@couchbase.com> Wed Oct 31 20:54:12 2018 -0700
tree 61ec3a402966cde41a0ce4079f87ff1258d2693d
parent b9d55c40e12be6cb4164dd154efa919040c617c7

[ASTERIXDB-2466][FUN] Implement window functions

- user model changes: yes
- storage format changes: no
- interface changes: no

Details:
- Implement window functions with SQL syntax:
  function() OVER ((PARTITION BY expr1, expr2, ...)? ORDER BY exprA, exprB, ...)
- Where supported functions are:
  ROW_NUMBER(), RANK(), DENSE_RANK(), PERCENT_RANK(), NTILE()

Change-Id: Ia28af8773cb11049c38d440c51b9c3cd1ed2bab4
Reviewed-on: https://asterix-gerrit.ics.uci.edu/3002
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Ali Alsuliman <ali.al.solaiman@gmail.com>

asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj

diff --git a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
index 13d1f8d..e19ee7a 100644
--- a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
+++ b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
@@ -166,6 +166,7 @@
 import org.apache.asterix.lang.common.clause.WhereClause;
 import org.apache.asterix.lang.sqlpp.expression.CaseExpression;
 import org.apache.asterix.lang.sqlpp.expression.SelectExpression;
+import org.apache.asterix.lang.sqlpp.expression.WindowExpression;
 import org.apache.asterix.lang.sqlpp.optype.JoinType;
 import org.apache.asterix.lang.sqlpp.optype.SetOpType;
 import org.apache.asterix.lang.sqlpp.struct.SetOperationInput;
@@ -2588,7 +2589,7 @@
 
 Expression FunctionCallExpr() throws ParseException:
 {
-  CallExpr callExpr;
+  Expression resultExpr;
   List<Expression> argList = new ArrayList<Expression>();
   Expression tmp = null;
   int arity = 0;
@@ -2596,6 +2597,10 @@
   String hint = null;
   boolean star = false;
   boolean distinct = false;
+  Token overToken = null;
+  Expression partitionExpr = null;
+  List<Expression> partitionExprs = new ArrayList<Expression>();
+  OrderbyClause orderByClause = null;
 }
 {
   funcName = FunctionName()
@@ -2634,7 +2639,7 @@
       if (signature == null) {
         signature = new FunctionSignature(funcName.dataverse, fqFunctionName, arity);
       }
-      callExpr = FunctionMapUtil.normalizedListInputFunctions(new CallExpr(signature,argList));
+      CallExpr callExpr = FunctionMapUtil.normalizedListInputFunctions(new CallExpr(signature,argList));
       if (hint != null) {
         if (hint.startsWith(INDEXED_NESTED_LOOP_JOIN_HINT)) {
           callExpr.addHint(IndexedNLJoinExpressionAnnotation.INSTANCE);
@@ -2643,8 +2648,29 @@
         }
       }
       callExpr.setSourceLocation(funcName.sourceLoc);
-      return callExpr;
+      resultExpr = callExpr;
     }
+
+  (
+    <OVER> { overToken = token; }
+    <LEFTPAREN>
+    (
+      <PARTITION> <BY>
+      partitionExpr = Expression() { partitionExprs.add(partitionExpr); }
+      ( <COMMA> partitionExpr = Expression() { partitionExprs.add(partitionExpr); } )*
+    )?
+    orderByClause = OrderbyClause()
+    <RIGHTPAREN>
+    {
+      WindowExpression winExp = new WindowExpression(callExpr, partitionExprs, orderByClause.getOrderbyList(),
+        orderByClause.getModifierList());
+      resultExpr = addSourceLocation(winExp, overToken);
+    }
+  )?
+
+  {
+     return resultExpr;
+  }
 }
 
 Expression ParenthesizedExpression() throws ParseException:
@@ -3393,7 +3419,9 @@
   | <ORDER : "order">
   | <OUTER : "outer">
   | <OUTPUT : "output">
+  | <OVER: "over">
   | <PATH : "path">
+  | <PARTITION : "partition">
   | <POLICY : "policy">
   | <PRESORTED : "pre-sorted">
   | <PRIMARY : "primary">