[CALCITE-1506] Push OVER Clause to underlying SQL via JDBC adapter

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.11.0
• Component/s: jdbc-adapter
• Assignee: Julian Hyde
• Reporter: Christian Tzolov
• Created: 23/Nov/16 12:12
• Updated: 01/Nov/18 18:56
• Resolved: 28/Nov/16 18:33

Description

The jdbc adapter adapter should push down the OVER clause for all dialects that support window functions.

At the moment the Rel to SQL conversion ignores the 'OVER(...)'. The RexOver expression is treated as a plain RexCall and the RexOver#window attribute is not converted into SQL.

For example if the following sql query (using Postgres dialect):

SELECT "id", "device_id", "transaction_value", "account_id", "ts_millis", MAX("ts_millis") OVER(partition by "device_id") as "last_version_number" 
FROM "HAWQ"."transaction"
WHERE "device_id" = 1445

is pushed down to the jdbc like this:

SELECT "id", "device_id", "transaction_value", "account_id", "ts_millis", MAX("ts_millis") AS "last_version_number"
FROM "transaction"
WHERE "device_id" = 1445

The OVER clause is completely dropped! Here is the plan:

JdbcToEnumerableConverter
  JdbcProject(id=[$0], device_id=[$1], transaction_value=[$2], account_id=[$3], ts_millis=[$4], last_version_number=[MAX($4) OVER (PARTITION BY $1 RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)])
    JdbcFilter(condition=[=($1, 1445)])
      JdbcTableScan(table=[[HAWQ, transaction]])

Issue Links

• relates to: CALCITE-1174 When generating SQL, translate SUM0(x) to COALESCE(SUM(x), 0)