support pg11 call syntax

[davecramer]

PostgreSQL 11 now has call func https://www.postgresql.org/docs/11/static/sql-call.html syntax

[vlsi]

1. Current implementation converts {call my_proc('whatever')} to select * from my_proc('whatever') and it fails with

ERROR: my_proc(unknown) is a procedure
To call a procedure, use CALL

2. If PreparedStatement(CALL my_proc('whatever')).executeQuery is used, then query produces no data:

FINEST:  FE=> Parse(stmt=null,query="CALL my_proc('whatever')",oids={})
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl sendBind
FINEST:  FE=> Bind(stmt=null,portal=null)
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl sendDescribePortal
FINEST:  FE=> Describe(portal=null)
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl sendExecute
FINEST:  FE=> Execute(portal=null,limit=0)
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl sendSync
FINEST:  FE=> Sync
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl processResults
FINEST:  <=BE ParseComplete [null]
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl processResults
FINEST:  <=BE BindComplete [unnamed]
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl processResults
FINEST:  <=BE NoData
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl receiveCommandStatus
FINEST:  <=BE CommandStatus(CALL)
Jul 23, 2018 9:21:09 PM org.postgresql.core.v3.QueryExecutorImpl receiveRFQ
FINEST:  <=BE ReadyForQuery(I)

3. When simple query mode is set (e.g. PGProperty.PREFER_QUERY_MODE.set(props, "simple"); ), then result is returned:

FINEST:  FE=> SimpleQuery(query="CALL my_proc('whatever')")
Jul 23, 2018 9:24:46 PM org.postgresql.core.v3.QueryExecutorImpl receiveFields
FINEST:  <=BE RowDescription(1)
Jul 23, 2018 9:24:46 PM org.postgresql.core.v3.QueryExecutorImpl receiveFields
FINEST:         Field(results,TEXT,65535,T)
Jul 23, 2018 9:24:46 PM org.postgresql.core.v3.QueryExecutorImpl processResults
FINEST:  <=BE DataRow(len=4)
Jul 23, 2018 9:24:46 PM org.postgresql.core.v3.QueryExecutorImpl receiveCommandStatus
FINEST:  <=BE CommandStatus(CALL)
Jul 23, 2018 9:24:46 PM org.postgresql.core.v3.QueryExecutorImpl receiveRFQ
FINEST:  <=BE ReadyForQuery(I)

[davecramer]

An interesting option is to optimistically call the function and if that fails then retry with call procedure. We could then cache the fact that it is a procedure. This causes some transaction issues, but we could wrap it in a savepoint. or alternatively create a wrapper function to do all of this.

[davecramer]

implemented property to allow #1560