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Make plan_cluster_use_sort cope with no IndexOptInfo for the target index.

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The original coding assumed that such a case represents caller error, but
actually get_relation_info will omit generating an IndexOptInfo for any
index it thinks is unsafe to use.  Therefore, handle this case by returning
"true" to indicate that a seqscan-and-sort is the preferred way to
implement the CLUSTER operation.  New bug in 9.1, no backpatch needed.
Per bug #5985 from Daniel Grace.
This commit is contained in:
Tom Lane
2011-04-20 17:43:34 -04:00
parent 395fcac299
commit 5b8e442953
1 changed files with 18 additions and 11 deletions
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29
src/backend/optimizer/plan/planner.c
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@ -3093,15 +3093,6 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid)
/* Build RelOptInfo */
rel = build_simple_rel(root, 1, RELOPT_BASEREL);
/*
* Rather than doing all the pushups that would be needed to use
* set_baserel_size_estimates, just do a quick hack for rows and width.
*/
rel->rows = rel->tuples;
rel->width = get_relation_data_width(tableOid, NULL);
root->total_table_pages = rel->pages;
/* Locate IndexOptInfo for the target index */
indexInfo = NULL;
foreach(lc, rel->indexlist)
@ -3110,9 +3101,25 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid)
if (indexInfo->indexoid == indexOid)
break;
}
/*
* It's possible that get_relation_info did not generate an IndexOptInfo
* for the desired index; this could happen if it's not yet reached its
* indcheckxmin usability horizon, or if it's a system index and we're
* ignoring system indexes. In such cases we should tell CLUSTER to not
* trust the index contents but use seqscan-and-sort.
*/
if (lc == NULL) /* not in the list? */
elog(ERROR, "index %u does not belong to table %u",
indexOid, tableOid);
return true; /* use sort */
/*
* Rather than doing all the pushups that would be needed to use
* set_baserel_size_estimates, just do a quick hack for rows and width.
*/
rel->rows = rel->tuples;
rel->width = get_relation_data_width(tableOid, NULL);
root->total_table_pages = rel->pages;
/*
* Determine eval cost of the index expressions, if any. We need to