[CALCITE-5233] Support for SQL syntax with parenthesis for outer join associativity

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: 1.31.0
• Assignee: Unassigned
• Reporter: Dirk
• Created: 11/Aug/22 19:54
• Updated: 12/Aug/22 22:59
• Resolved: 12/Aug/22 22:59

Description

Outer joins are not associative ( .e.g.  "(t1 LEFT JOIN t2) LEFT JOIN  t3" != "t1 LEFT JOIN  (t2 LEFT JOIN  t3)" ). For this SQL allows using parenthesis to specify associativity. For example the MySQL docs (https://dev.mysql.com/doc/refman/5.7/en/nested-join-optimization.html ) have this as an example:
SELECT * FROM (t1 LEFT JOIN t2 ON t1.a=t2.a) LEFT JOIN t3 ON t2.b=t3.b OR t2.b IS NULL;
vs.
SELECT * FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.b=t3.b OR t2.b IS NULL) ON t1.a=t2.a;

The Calcite parser fails parsing this with a "Non-query expression encountered in illegal context" message (see stack trace of calcite 1.30 below).
What I'd like to request as a feature is supporting parenthesis for join order in parser and SQL formatting. Support on a grammar, parsing, AST and formatting would be sufficient for me.

Stack trace parsing the first example:{}

org.apache.calcite.sql.parser.SqlParseException: Non-query expression encountered in illegal context
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.convertException(SqlParserImpl.java:389)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.normalizeException(SqlParserImpl.java:153)
    at org.apache.calcite.sql.parser.SqlParser.handleException(SqlParser.java:145)
    at org.apache.calcite.sql.parser.SqlParser.parseQuery(SqlParser.java:160)
    at com.linkedin.espresso.store.sql.TestCalciteParser.testCalciteQueryPrototyping(TestCalciteParser.java:70)
    ... 24 more
Caused by: org.apache.calcite.runtime.CalciteException: Non-query expression encountered in illegal context
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
    at org.apache.calcite.runtime.Resources$ExInstWithCause.ex(Resources.java:505)
    at org.apache.calcite.runtime.Resources$ExInst.ex(Resources.java:599)
    at org.apache.calcite.sql.SqlUtil.newContextException(SqlUtil.java:932)
    at org.apache.calcite.sql.SqlUtil.newContextException(SqlUtil.java:917)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.checkNonQueryExpression(SqlParserImpl.java:312)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.Expression3(SqlParserImpl.java:16502)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.Expression2b(SqlParserImpl.java:16155)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.Expression2(SqlParserImpl.java:16196)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.Expression(SqlParserImpl.java:16126)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.LeafQueryOrExpr(SqlParserImpl.java:16103)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.QueryOrExpr(SqlParserImpl.java:15557)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.OrderedQueryOrExpr(SqlParserImpl.java:505)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.ParenthesizedExpression(SqlParserImpl.java:666)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.TableRef2(SqlParserImpl.java:9343)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.TableRef(SqlParserImpl.java:9268)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.FromClause(SqlParserImpl.java:9158)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.SqlSelect(SqlParserImpl.java:4419)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.LeafQuery(SqlParserImpl.java:631)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.LeafQueryOrExpr(SqlParserImpl.java:16109)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.QueryOrExpr(SqlParserImpl.java:15557)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.OrderedQueryOrExpr(SqlParserImpl.java:505)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.SqlStmt(SqlParserImpl.java:3790)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.SqlStmtEof(SqlParserImpl.java:3828)
    at org.apache.calcite.sql.parser.impl.SqlParserImpl.parseSqlStmtEof(SqlParserImpl.java:201)
    at org.apache.calcite.sql.parser.SqlParser.parseQuery(SqlParser.java:158)
    ... 25 more

Issue Links

• is related to: CALCITE-35 Support parenthesized sub-clause in JOIN