mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-22 10:33:22 +02:00
As of 9.2, with the --section option, it is very important that the concept of "pre data", "data", and "post data" sections of the output be honored strictly; else a dump divided into separate sectional files might be unrestorable. However, the dependency-sorting logic knew nothing of sections and would happily select output orderings that didn't fit that structure. Doing so was mostly harmless before 9.2, but now we need to be sure it doesn't do that. To fix, create dummy objects representing the section boundaries and add dependencies between them and all the normal objects. (This might sound expensive but it seems to only add a percent or two to pg_dump's runtime.) This also fixes a problem introduced in 9.1 by the feature that allows incomplete GROUP BY lists when a primary key is given in GROUP BY. That means that views can depend on primary key constraints. Previously, pg_dump would deal with that by simply emitting the primary key constraint before the view definition (and hence before the data section of the output). That's bad enough for simple serial restores, where creating an index before the data is loaded works, but is undesirable for speed reasons. But it could lead to outright failure of parallel restores, as seen in bug #6699 from Joe Van Dyk. That happened because pg_restore would switch into parallel mode as soon as it reached the constraint, and then very possibly would try to emit the view definition before the primary key was committed (as a consequence of another bug that causes the view not to be correctly marked as depending on the constraint). Adding the section boundary constraints forces the dependency-sorting code to break the view into separate table and rule declarations, allowing the rule, and hence the primary key constraint it depends on, to revert to their intended location in the post-data section. This also somewhat accidentally works around the bogus-dependency-marking problem, because the rule will be correctly shown as depending on the constraint, so parallel pg_restore will now do the right thing. (We will fix the bogus-dependency problem for real in a separate patch, but that patch is not easily back-portable to 9.1, so the fact that this patch is enough to dodge the only known symptom is fortunate.) Back-patch to 9.1, except for the hunk that adds verification that the finished archive TOC list is in correct section order; the place where it was convenient to add that doesn't exist in 9.1. |
||
---|---|---|
config | ||
contrib | ||
doc | ||
src | ||
.gitignore | ||
aclocal.m4 | ||
configure | ||
configure.in | ||
COPYRIGHT | ||
GNUmakefile.in | ||
Makefile | ||
README | ||
README.git |
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: http://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. Changes between all PostgreSQL releases are recorded in the file HISTORY. 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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.