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| author | Simon Riggs <simon@2ndQuadrant.com> | 2018-04-12 11:22:56 +0100 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2018-04-12 11:22:56 +0100 |
| commit | 08ea7a2291db21a618d19d612c8060cda68f1892 (patch) | |
| tree | 4d10675439742c7206e089bd21e793332562ae83 /src/backend/executor/README | |
| parent | c9c875a28fa6cbc38c227fb9e656dd7be948166f (diff) | |
Revert MERGE patch
This reverts commits d204ef63776b8a00ca220adec23979091564e465,
83454e3c2b28141c0db01c7d2027e01040df5249 and a few more commits thereafter
(complete list at the end) related to MERGE feature.
While the feature was fully functional, with sufficient test coverage and
necessary documentation, it was felt that some parts of the executor and
parse-analyzer can use a different design and it wasn't possible to do that in
the available time. So it was decided to revert the patch for PG11 and retry
again in the future.
Thanks again to all reviewers and bug reporters.
List of commits reverted, in reverse chronological order:
f1464c5380 Improve parse representation for MERGE
ddb4158579 MERGE syntax diagram correction
530e69e59b Allow cpluspluscheck to pass by renaming variable
01b88b4df5 MERGE minor errata
3af7b2b0d4 MERGE fix variable warning in non-assert builds
a5d86181ec MERGE INSERT allows only one VALUES clause
4b2d44031f MERGE post-commit review
4923550c20 Tab completion for MERGE
aa3faa3c7a WITH support in MERGE
83454e3c2b New files for MERGE
d204ef6377 MERGE SQL Command following SQL:2016
Author: Pavan Deolasee
Reviewed-by: Michael Paquier
Diffstat (limited to 'src/backend/executor/README')
| -rw-r--r-- | src/backend/executor/README | 11 |
1 files changed, 0 insertions, 11 deletions
diff --git a/src/backend/executor/README b/src/backend/executor/README index 67736805c26..0d7cd552eb6 100644 --- a/src/backend/executor/README +++ b/src/backend/executor/README @@ -37,17 +37,6 @@ the plan tree returns the computed tuples to be updated, plus a "junk" one. For DELETE, the plan tree need only deliver a CTID column, and the ModifyTable node visits each of those rows and marks the row deleted. -MERGE runs one generic plan that returns candidate target rows. Each row -consists of a super-row that contains all the columns needed by any of the -individual actions, plus CTID and TABLEOID junk columns. The CTID column is -required to know if a matching target row was found or not and the TABLEOID -column is needed to find the underlying target partition, in case when the -target table is a partitioned table. When a matching target tuple is found, -the CTID column identifies the matching tuple and we attempt to activate -WHEN MATCHED actions. If a matching tuple is not found, then CTID column is -NULL and we attempt to activate WHEN NOT MATCHED actions. Once we know which -action is activated we form the final result row and apply only those changes. - XXX a great deal more documentation needs to be written here... |