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authorNeil Conway <neilc@samurai.com>2005-04-24 11:46:21 +0000
committerNeil Conway <neilc@samurai.com>2005-04-24 11:46:21 +0000
commit947eb975605c2449bfd7a8c80c7b1de9bd98ff96 (patch)
tree35359babfcb48400693c3a032955e10ea480d4a7 /src/backend/executor/nodeResult.c
parenta7f2a788ee2ec44b7f1883d8fc724c25a49cc01b (diff)
downloadpostgresql-947eb975605c2449bfd7a8c80c7b1de9bd98ff96.tar.gz
postgresql-947eb975605c2449bfd7a8c80c7b1de9bd98ff96.zip
Update some comments to use SQL examples rather than QUEL. From Simon
Riggs.
Diffstat (limited to 'src/backend/executor/nodeResult.c')
-rw-r--r--src/backend/executor/nodeResult.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/src/backend/executor/nodeResult.c b/src/backend/executor/nodeResult.c
index abc94a2cf12..ee6c91cb9dc 100644
--- a/src/backend/executor/nodeResult.c
+++ b/src/backend/executor/nodeResult.c
@@ -8,15 +8,13 @@
* Result nodes are used in queries where no relations are scanned.
* Examples of such queries are:
*
- * retrieve (x = 1)
- * and
- * append emp (name = "mike", salary = 15000)
+ * select 1 * 2
*
* Result nodes are also used to optimise queries with constant
* qualifications (ie, quals that do not depend on the scanned data),
* such as:
*
- * retrieve (emp.all) where 2 > 1
+ * select * from emp where 2 > 1
*
* In this case, the plan generated is
*
@@ -24,9 +22,10 @@
* /
* SeqScan (emp.all)
*
- * At runtime, the Result node evaluates the constant qual once.
- * If it's false, we can return an empty result set without running
- * the controlled plan at all. If it's true, we run the controlled
+ * At runtime, the Result node evaluates the constant qual once,
+ * which is shown by EXPLAIN as a One-Time Filter. If it's
+ * false, we can return an empty result set without running the
+ * controlled plan at all. If it's true, we run the controlled
* plan normally and pass back the results.
*
*
@@ -34,7 +33,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.29 2004/12/31 21:59:45 pgsql Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.30 2005/04/24 11:46:21 neilc Exp $
*
*-------------------------------------------------------------------------
*/