Go to file
Peter Geoghegan eba775345d Avoid amcheck inline compression false positives.
The previous tacit assumption that index_form_tuple() hides differences
in the TOAST state of its input datums was wrong.  Normalize input
varlena datums by decompressing compressed values, and forming a new
index tuple for fingerprinting using uncompressed inputs.  The final
normalized representation may actually be compressed once again within
index_form_tuple(), though that shouldn't matter.  When the original
tuple is found to have no datums that are compressed inline, fingerprint
the original tuple directly.

Normalization avoids false positive reports of corruption in certain
cases.  For example, the executor can apply toasting with some inline
compression to an entire heap tuple because its input has a single
external TOAST pointer.  Varlena datums for other attributes that are
not particularly good candidates for inline compression can be
compressed in the heap tuple in passing, without the representation of
the same values in index tuples ever receiving concomitant inline
compression.

Add a test case to recreate the issue in a simpler though less realistic
way: by exploiting differences in pg_attribute.attstorage between heap
and index relations.

This bug was discovered by me during testing of an upcoming set of nbtree
enhancements.  It was also independently reported by Andreas Kunert, as
bug #15597.  His test case was rather more realistic than the one I
ended up using.

Bug: #15597
Discussion: https://postgr.es/m/CAH2-WznrVd9ie+TTJ45nDT+v2nUt6YJwQrT9SebCdQKtAvfPZw@mail.gmail.com
Discussion: https://postgr.es/m/15597-294e5d3e7f01c407@postgresql.org
Backpatch: 11-, where heapallindexed verification was introduced.
2019-02-06 15:54:19 -08:00
config configure: More use of AC_ARG_VAR 2019-01-18 08:38:34 +01:00
contrib Avoid amcheck inline compression false positives. 2019-02-06 15:54:19 -08:00
doc Doc: in each release branch, keep only that branch's own release notes. 2019-02-04 19:18:49 -05:00
src Hide cascade messages in collate tests 2019-02-06 22:17:57 +01:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.gitattributes Remove contrib/tsearch2. 2017-02-13 11:06:11 -05:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
COPYRIGHT Update copyright for 2019 2019-01-02 12:44:25 -05:00
GNUmakefile.in Process EXTRA_INSTALL serially, during the first temp-install. 2018-12-31 13:54:38 -08:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Fix non-GNU makefiles for AIX make. 2017-11-30 00:57:22 -08:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
aclocal.m4 Fix configure's AC_CHECK_DECLS tests to work correctly with clang. 2018-11-19 12:01:47 -05:00
configure Second try at fixing ecpglib thread-safety problem. 2019-01-21 16:17:10 -05:00
configure.in Second try at fixing ecpglib thread-safety problem. 2019-01-21 16:17:10 -05:00

README

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.