Opened 11 years ago
Closed 11 years ago
#1797 closed defect (fixed)
validatetopology error when asking for column names
|Reported by:||jomarlla||Owned by:||strk|
Something is going wrong with the create temp table when one try to use select (validatetopology ('t1')).*;
This is ok.
s9=# select validatetopology ('t1'); validatetopology ------------------ (0 rows)
now the error:
s9=# select (validatetopology ('t1')).*; ERROR: relation "face_check" already exists CONTEXT: SQL statement "CREATE TEMP TABLE face_check ON COMMIT DROP AS SELECT face_id, topology.ST_GetFaceGeometry('t1', face_id) as geom, mbr FROM t1.face WHERE face_id > 0" PL/pgSQL function "validatetopology" line 204 at EXECUTE statement
Change History (3)
comment:1 by , 11 years ago
comment:2 by , 11 years ago
A quick talk with andres on #postgresql @freenode suggests there are a lot of performance implications too in the use of (srf()).* syntax. See these:
comment:3 by , 11 years ago
|Status:||new → closed|
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Ouch. I think this is due to what could be considered like a bug (IMHO) of PostgreSQL, that is the fact that a set-returning function called with the syntax: (srf()).* gets expanded as multiple calls to the function (one per returning column) and results in actual calls rather than reusing the result from the function (I think the function is STABLE).
So, since the function creates a temporary table, with transaction lifetime, the second call finds the table already existing and bails out.
Not sure how could this be fixed, except maybe by avoiding the creation of the temporary table (which would slow things down considerably).