Re: [HACKERS] [COMMITTERS] pgsql: Release note updates. - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: [HACKERS] [COMMITTERS] pgsql: Release note updates.
Date
Msg-id 20170207115357.ojk6wlewdcu36afa@alvherre.pgsql
Whole thread Raw
Responses Re: [HACKERS] [COMMITTERS] pgsql: Release note updates.  (Pavan Deolasee <pavan.deolasee@gmail.com>)
Re: [HACKERS] [COMMITTERS] pgsql: Release note updates.  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Release note updates.
> 
> Add item for last-minute CREATE INDEX CONCURRENTLY fix.

Hi,

Sorry for not noticing earlier, but there is a bug in the notes:

+      If <command>CREATE INDEX CONCURRENTLY</> was used to build an index
+      that depends on a column not previously indexed, then rows inserted
+      or updated by transactions that ran concurrently with
+      the <command>CREATE INDEX</> command could have received incorrect
+      index entries.

CIC bug does not affect inserted rows, only updated rows, since the
bogus bitmap is only used to compute whether to omit index tuples for
HOT considerations.

Also, the bollixed rows do not receive incorrect index entries -- they
just do not receive any index entry at all.

May I suggest

+      If <command>CREATE INDEX CONCURRENTLY</> was used to build an index
+      that depends on a column not previously indexed, then rows
+      updated by transactions that ran concurrently with
+      the <command>CREATE INDEX</> command could have missed receiving
+      index entries.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



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