Revues de code

Correctifs appliqués

Magnus Hagander a poussé :

Alvaro Herrera a poussé :

Tom Lane a poussé :

  • Change FK trigger creation order to better support self-referential FKs. When a foreign-key constraint references another column of the same table, row updates will queue both the PK's ON UPDATE action and the FK's CHECK action in the same event. The ON UPDATE action must execute first, else the CHECK will check a non-final state of the row and possibly throw an inappropriate error, as seen in bug #6268 from Roman Lytovchenko. Now, the firing order of multiple triggers for the same event is determined by the sort order of their pg_trigger.tgnames, and the auto-generated names we use for FK triggers are "RI_ConstraintTrigger_NNNN" where NNNN is the trigger OID. So most of the time the firing order is the same as creation order, and so rearranging the creation order fixes it. This patch will fail to fix the problem if the OID counter wraps around or adds a decimal digit (eg, from 99999 to 100000) while we are creating the triggers for an FK constraint. Given the small odds of that, and the low usage of self-referential FKs, we'll live with that solution in the back branches. A better fix is to change the auto-generated names for FK triggers, but it seems unwise to do that in stable branches because there may be client code that depends on the naming convention. We'll fix it that way in HEAD in a separate patch. Back-patch to all supported branches, since this bug has existed for a long time.
  • Change FK trigger naming convention to fix self-referential FKs. Use names like "RI_ConstraintTrigger_a_NNNN" for FK action triggers and "RI_ConstraintTrigger_c_NNNN" for FK check triggers. This ensures the action trigger fires first in self-referential cases where the very same row update fires both an action and a check trigger. This change provides a non-probabilistic solution for bug #6268, at the risk that it could break client code that is making assumptions about the exact names assigned to auto-generated FK triggers. Hence, change this in HEAD only. No need for forced initdb since old triggers continue to work fine.
  • Improve planner's ability to recognize cases where an IN's RHS is unique. If the right-hand side of a semijoin is unique, then we can treat it like a normal join (or another way to say that is: we don't need to explicitly unique-ify the data before doing it as a normal join). We were recognizing such cases when the RHS was a sub-query with appropriate DISTINCT or GROUP BY decoration, but there's another way: if the RHS is a plain relation with unique indexes, we can check if any of the indexes prove the output is unique. Most of the infrastructure for that was there already in the join removal code, though I had to rearrange it a bit. Per reflection about a recent example in pgsql-performance.
  • Typo fixes. expect -> except, noted by Andrew Dunstan. Also, "cannot" seems more readable here than "can not", per David Wheeler.
  • Add simple script to check for right recursion in Bison grammars. We should generally use left-recursion not right-recursion to parse lists. Bison hasn't got any built-in way to check for this type of inefficiency, and I didn't find anything on the net in a quick search, so I wrote a little Perl script to do it. Add to src/tools/ so we don't have to re-invent this wheel next time we wonder if we're doing anything stupid. Currently, the only place that seems to need fixing is plpgsql's stmt_else production, so the problem doesn't appear to be common enough to warrant trying to include such a test in our standard build process. If we did want to do that, we'd need a way to ignore some false positives, such as a_expr := '-' a_expr
  • Avoid recursion while processing ELSIF lists in plpgsql. The original implementation of ELSIF in plpgsql converted the construct into nested simple IF statements. This was prone to stack overflow with long ELSIF lists, in two different ways. First, it's difficult to generate the parsetree without using right-recursion in the bison grammar, and that's prone to parser stack overflow since nothing can be reduced until the whole list has been read. Second, we'd recurse during execution, thus creating an unnecessary risk of execution-time stack overflow. Rewrite so that the ELSIF list is represented as a flat list, scanned via iteration not recursion, and generated through left-recursion in the grammar. Per a gripe from Håvard Kongsgård.
  • Update docs to point to the timezone library's new home at IANA. The recent unpleasantness with copyrights has accelerated a move that was already in planning.
  • De-parallelize ecpg build some more. Make sure ecpg/include/ is rebuilt before the other subdirectories, so that ecpg_config.h is up to date. This is not likely to matter during production builds, only development, so no back-patch.
  • Fix assorted bogosities in cash_in() and cash_out(). cash_out failed to handle multiple-byte thousands separators, as per bug #6277 from Alexander Law. In addition, cash_in didn't handle that either, nor could it handle multiple-byte positive_sign. Both routines failed to support multiple-byte mon_decimal_point, which I did not think was worth changing, but at least now they check for the possibility and fall back to using '.' rather than emitting invalid output. Also, make cash_in handle trailing negative signs, which formerly it would reject. Since cash_out generates trailing negative signs whenever the locale tells it to, this last omission represents a fail-to-reload-dumped-data bug. IMO that justifies patching this all the way back.
  • Further improvement of make_greater_string. Make sure that it considers all the possibilities that the old code did, instead of trying only one possibility per character position. To keep the runtime in bounds, instead tweak the character incrementers to not try every possible multibyte character code. Remove unnecessary logic to restore the old character value on failure. Additional comment and formatting cleanup.
  • Support more locale-specific formatting options in cash_out(). The POSIX spec defines locale fields for controlling the ordering of the value, sign, and currency symbol in monetary output, but cash_out only supported a small subset of these options. Fully implement p/n_sign_posn, p/n_cs_precedes, and p/n_sep_by_space per spec. Fix up cash_in so that it will accept all these format variants. Also, make sure that thousands_sep is only inserted to the left of the decimal point, as required by spec. Per bug #6144 from Eduard Kracmar and discussion of bug #6277. This patch includes some ideas from Alexander Lakhin's proposed patch, though it is very different in detail.

Bruce Momjian a poussé :

Heikki Linnakangas a poussé :

  • Fix the number of lwlocks needed by the "fast path" lock patch. It needs one lock per backend or auxiliary process - the need for a lock for each aux processes was not accounted for in NumLWLocks(). No-one noticed, because the three locks needed for the three aux processes fit into the few extra lwlocks we allocate for 3rd party modules that don't call RequestAddinLWLocks() (NUM_USER_DEFINED_LWLOCKS, 4 by default).

Robert Haas a poussé :

Correctifs rejetés (à ce jour)

  • Pas de déception cette semaine :-)

Correctifs en attente

  • Fujii Masao and Jun Ishiduka traded revisions of the patch to allow taking a base backup from a hot standby.
  • Shigeru HANADA sent in two revisions of patches for a PostgreSQL FDW, along with some generic helper functions and new documentation on how to write FDWs.
  • Heikki Linnakangas sent in another revision of the patch to add multiple tuples at once in COPY.
  • Simon Riggs sent in two revisions of a patch to fix an issue where hot backup fails at rsync fails at pg_clog when under load.
  • Kerem Kat sent in another revision of the patch to add CORRESPONDING TO set operations.
  • Pavel Stehule sent in another revision of the patch that allows PL/pgsql to make arrays of any %TYPE declared.
  • Alexander Korotkov sent in another revision of the patch to collect statistics for array columns.
  • Robert Haas sent in a couple of patches he was using to analyze the slowness of COUNT(*) in the index-only scan case.
  • Simon Riggs sent in two revisions of a patch to speed up hot standbys in the subtransaction case.
  • Robert Haas sent in a patch to speed up unlogged tables.
  • Robert Haas sent in a patch that initializes each PGPROC's myProcLocks just once at postmaster startup rather than every time the PGPROC is handed out to a backend.