ttOptShowJoinOrder

Description

Returns the join order of the last prepared or executed SQL statement (SELECT, UPDATE, DELETE, and INSERT SELECT) in the current transaction. For a join order to be collected, use ttOptSetFlag('ShowJoinOrder', 1) or set the ttIsql "ShowJoinOrder" command to ON (1) first in the same transaction. AUTOCOMMIT must be off when using either of these commands. The join order is represented by table names.

Required privilege

This procedure requires no privilege.

Syntax

ttOptShowJoinOrder()

Parameters

ttOptShowJoinOrder has no parameters.

Result set

ttOptShowJoinOrder returns the result:

Column	Type	Description
`tblName`	TT VARCHAR (4096) NOT NULL	Table names, including owner name quantifiers and correlation name for each table if specified. Table names are returned in parentheses.

Example

>AUTOCOMMIT 0;
> CALL ttOptSetFlag ('ShowJoinOrder', 1);
>PREPARE SELECT * FROM t1;
>CALL ttOptShowJoinOrder();
>( T1 )

Note

You must call ttOptSetFlag('ShowJoinOrder', 1) or set the ttIsql "ShowJoinOrder" command to ON (1) before using this procedure.

This procedure works within one transaction and is not persistent across transactions.