transaction, unless rolled back or overridden by a SET clause for the same
variable attached to a surrounding function call. Per discussion, these
seem the best semantics. Note that this is an INCOMPATIBLE CHANGE: in 8.0
through 8.2, SET LOCAL's effects disappeared at subtransaction commit
(leading to behavior that made little sense at the SQL level).
I took advantage of the opportunity to rewrite and simplify the GUC variable
save/restore logic a little bit. The old idea of a "tentative" value is gone;
it was a hangover from before we had a stack. Also, we no longer need a stack
entry for every nesting level, but only for those in which a variable's value
actually changed.
rows will normally never obtain an XID at all. We already did things this way
for subtransactions, but this patch extends the concept to top-level
transactions. In applications where there are lots of short read-only
transactions, this should improve performance noticeably; not so much from
removal of the actual XID-assignments, as from reduction of overhead that's
driven by the rate of XID consumption. We add a concept of a "virtual
transaction ID" so that active transactions can be uniquely identified even
if they don't have a regular XID. This is a much lighter-weight concept:
uniqueness of VXIDs is only guaranteed over the short term, and no on-disk
record is made about them.
Florian Pflug, with some editorialization by Tom.
(Actually, it works as a plain statement too, but I didn't document that
because it seems a bit useless.) Unify VariableResetStmt with
VariableSetStmt, and clean up some ancient cruft in the representation of
same.
There are still some loose ends: I didn't do anything about the SET FROM
CURRENT idea yet, and it's not real clear whether we are happy with the
interaction of SET LOCAL with function-local settings. The documentation
is a bit spartan, too.
but just hardwire the specified timezone database path into the executable.
Per discussion, this avoids some packaging disadvantages of using a
symlink.
This prevents needing to do complex and poorly-defined updates of the
mapping table if the new parser has different token types than the old.
Per discussion.
init options of the template as top-level options in the syntax. This also
makes ALTER a bit easier to use, since options can be replaced individually.
I also made these statements verify that the tmplinit method will accept
the new settings before they get stored; in the original coding you didn't
find out about mistakes until the dictionary got invoked.
Under the hood, init methods now get options as a List of DefElem instead
of a raw text string --- that lets tsearch use existing options-pushing code
instead of duplicating functionality.
pages for the new SQL commands. I also committed Bruce's text search
introductory chapter, as-is except for fixing some markup errors,
so that there would be a place for the reference pages to link to.
Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.
Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.
> A third idea would be for a heap scan to check if all rows are visible
> and if so set a per-table flag which can be checked by index scans.
> Any change to the table would have to clear the flag. To detect
> changes during the heap scan a counter could be set at the start and
> checked at the end --- if it is the same, the table has not been
> modified --- any table change would increment the counter.
certain corner cases. Per discussion, the code does what we want, but
it really needs to be documented that these functions act differently
from regexp_matches.
that cached compiled patterns will still be there when the function is next
called. Clean up looping logic, thereby fixing bug identified by Pavel
Stehule. Share setup code between the two functions, add some comments, and
avoid risky mixing of int and size_t variables. Clean up the documentation a
tad, and accept all the flag characters mentioned in table 9-19 rather than
just a subset.
displayed in the postmaster log. This avoids Windows-specific problems with
localized time zone names that are in the wrong encoding, and generally seems
like a good idea to forestall other potential platform-dependent issues.
To preserve the existing behavior that all backends will log in the same time
zone, create a new GUC variable log_timezone that can only be changed on a
system-wide basis, and reference log-related calculations to that zone instead
of the TimeZone variable.
This fixes the issue reported by Hiroshi Saito that timestamps printed by
xlog.c startup could be improperly localized on Windows. We still need a
simpler patch for that problem in the back branches, however.
so that we will be able to create a cookie for all processes for CSVlogs.
It is set wherever MyProcPid is set. Take the opportunity to remove the now
unnecessary session-only restriction on the %s and %c escapes in log_line_prefix.
before reporting a transaction committed. Data consistency is still
guaranteed (unlike setting fsync = off), but a crash may lose the effects
of the last few transactions. Patch by Simon, some editorialization by Tom.
sugar for PL/PgSQL set-returning functions that want to return the result
of evaluating a query; it should also be more efficient than repeated
RETURN NEXT statements. Based on an earlier patch from Pavel Stehule.
and fsync WAL at convenient intervals. For the moment it just tries to
offload this work from backends, but soon it will be responsible for
guaranteeing a maximum delay before asynchronously-committed transactions
will be flushed to disk.
This is a portion of Simon Riggs' async-commit patch, committed to CVS
separately because a background WAL writer seems like it might be a good idea
independently of the async-commit feature. I rebased walwriter.c on
bgwriter.c because it seemed like a more appropriate way of handling signals;
while the startup/shutdown logic in postmaster.c is more like autovac because
we want walwriter to quit before we start the shutdown checkpoint.
I/O utilization, per discussion.
While at it, lower the autovacuum vacuum and analyze threshold values to 50
tuples. It is a bit higher (i.e. more conservative) than what I originally
proposed but much better than the old values for small tables.
against a Unix server, and Windows-specific server-side authentication
using SSPI "negotiate" method (Kerberos or NTLM).
Only builds properly with MSVC for now.
name. With this patch, it is always possible for the user to qualify a
plpgsql variable name if needed to avoid ambiguity. While there is much more
work to be done in this area, this simple change removes one unnecessary
incompatibility with Oracle. Per discussion.
of variable substitution and plan caching behavior in dedicated sections.
(A lot of this material existed already, but was scattered in various places
in the chapter.) Reorganize material a little bit, mostly to try to avoid
diving into deep details in the first introductory sections. Document some
fine points that had escaped treatment before, notably the ability to qualify
plpgsql variable names with block labels. Some minor wordsmithing here and
there.
literally, whether quoted or not. Since we allow $ as a character within
identifiers, this behavior is useful, whereas the previous behavior of
treating it as the regexp ending anchor was nearly useless given that the
pattern is automatically anchored anyway. This affects the arguments of
psql's \d commands as well as pg_dump's -n and -t switches. Per discussion.
PGconn. Invent a new libpq connection-status function,
PQconnectionUsedPassword() that returns true if the server
demanded a password during authentication, false otherwise.
This may be useful to clients in general, but is immediately
useful to help plug a privilege escalation path in dblink.
Per list discussion and design proposed by Tom Lane.
