strings. This is consistent with SQL conventions, and since Bruce
already changed initdb in a way that assumed it worked like this, seems
we'd better make it work like this.
< This would be beneficial when there are few distinct values.
> This would be beneficial when there are few distinct values. This is
> already used by GROUP BY.
946d946
< * Allow DISTINCT to use hashing like GROUP BY
<
390d388
<
453c451
< removed or have its heap and index files truncated. One
> be removed or have its heap and index files truncated. One
< * Use a phantom command counter for nested subtransactions to reduce
< per-tuple overhead
sake of brevity and clarity.
Make pg_reload_conf(), pg_rotate_logfile(), and pg_cancel_backend()
return a boolean rather than an integer to indicate success or failure.
Along the way, make some minor cleanups to dbsize.c -- in particular,
use elog() rather than ereport() for "shouldn't happen" error
conditions, and remove some of the more flagrant violations of the
Postgres indentation conventions.
Catalog version bumped.
the builtin functions (although some more entries are still needed),
and remove the duplicate index entries that have been causing
collateindex.pl warnings. Consistently use "int" and "bigint", rather
than a mix of "int", "integer", "int4", "bigint", and "int8". Make
parenthesis style in syntax examples more consistent. Various
copy-editing for newly-added documentation and SGML markup fixes.
particular the addition of bitmap scans and the relaxation of rules
about when multicolumn indexes can be used. Also some minor editorial
work in other parts of the chapter.
rather than "-" for the "dash" character. Correct SGML markup. Make
references to the names of contributors more consistent. Rewrite a bit
of prose, and make some other similar cleanups.
in the zic database or zone names found in the date token table. This
preserves the old ability to do AT TIME ZONE 'PST' along with the new
ability to do AT TIME ZONE 'PST8PDT'. Per gripe from Bricklen Anderson.
Also, fix some inconsistencies in usage of TZ_STRLEN_MAX --- the old
code had the potential for one-byte buffer overruns, though given
alignment considerations it's unlikely there was any real risk.
for procedural languages. This replaces the hard-wired table I had
originally proposed as a stopgap solution. For the moment, the initial
contents only include languages shipped with the core distribution.
as per my recent proposal. For now the template data is hard-wired in
proclang.c --- this should be replaced later by a new shared system
catalog, but we don't want to force initdb during 8.1 beta. This change
lets us cleanly load existing dump files even if they contain outright
wrong information about a PL's support functions, such as a wrong path
to the shared library or a missing validator function. Also, we can
revert the recent kluges to make pg_dump dump PL support functions that
are stored in pg_catalog.
While at it, I removed the code in pg_regress that replaced $libdir
with a hardcoded path for temporary installations. This is no longer
needed given our support for relocatable installations.
< cmin/cmax pair and is stored in local memory.
> cmin/cmax pair and is stored in local memory. Another idea is to
> store both cmin and cmax only in local memory.
< have its heap and index files truncated. One issue is
< that no other backend should be able to add to the table
< at the same time, which is something that is currently
< allowed.
> removed or have its heap and index files truncated. One
> issue is that no other backend should be able to add to
> the table at the same time, which is something that is
> currently allowed.
> o Allow COPY on a newly-created table to skip WAL logging
450a452,456
> On crash recovery, the table involved in the COPY would
> have its heap and index files truncated. One issue is
> that no other backend should be able to add to the table
> at the same time, which is something that is currently
> allowed.
> * Use UTF8 encoding for NLS messages so all server encodings can
> read them properly
< o %Add support for Unicode
<
< To fix this, the data needs to be converted to/from UTF16/UTF8
< so the Win32 wcscoll() can be used, and perhaps other functions
< like towupper(). However, UTF8 already works with normal
< locales but provides no ordering or character set classes.
< could only see committed rows from another transaction. However,
> could only see rows from another completed transaction. However,
981c981
< proper visibility of the row, for example, for cursors.
> proper visibility of the row's cmin, for example, for cursors.
* Merge xmin/xmax/cmin/cmax back into three header fields
Before subtransactions, there used to be only three fields needed to
store these four values. This was possible because only the current
transaction looks at the cmin/cmax values. If the current transaction
created and expired the row the fields stored where xmin (same as
xmax), cmin, cmax, and if the transaction was expiring a row from a
another transaction, the fields stored were xmin (cmin was not
needed), xmax, and cmax. Such a system worked because a transaction
could only see committed rows from another transaction. However,
subtransactions can see rows from outer transactions, and once the
subtransaction completes, the outer transaction continues, requiring
the storage of all four fields. With subtransactions, an outer
transaction can create a row, a subtransaction expire it, and when the
subtransaction completes, the outer transaction still has to have
proper visibility of the row, for example, for cursors.
One possible solution is to create a phantom cid which represents a
cmin/cmax pair and is stored in local memory.
< * Maintain a map of recently-expired rows
<
< This allows vacuum to target specific pages for possible free space
< without requiring a sequential scan.
<
Update entry:
> One complexity is that index entries still have to be vacuumed, and
> doing this without an index scan (by using the heap values to find the
> index entry) might be slow and unreliable, especially for user-defined
> index functions.
