access information about the prepared statements that are available
in the current session. Original patch from Joachim Wieland, various
improvements by Neil Conway.
The "statement" column of the view contains the literal query string
sent by the client, without any rewriting or pretty printing. This
means that prepared statements created via SQL will be prefixed with
"PREPARE ... AS ", whereas those prepared via the FE/BE protocol will
not. That is unfortunate, but discussion on -patches did not yield an
efficient way to improve this, and there is some merit in returning
exactly what the client sent to the backend.
Catalog version bumped, regression tests updated.
< STABLE | DEFAULT ]. [wallog]
> STABLE | DEFAULT ]. Tables using non-default logging should not use
> referential integrity with default-logging tables, and tables using
> stable logging probably can not have indexes. [wallog]
< the table. Another option is to avoid transaction logging entirely
< and truncate or drop the table on crash recovery. These should be
< implemented using ALTER TABLE, e.g. ALTER TABLE PERSISTENCE [ DROP |
< TRUNCATE | STABLE | DEFAULT ]. [wallog]
> the table. This would affect COPY, and perhaps INSERT/UPDATE too.
> Another option is to avoid transaction logging entirely and truncate
> or drop the table on crash recovery. These should be implemented
> using ALTER TABLE, e.g. ALTER TABLE PERSISTENCE [ DROP | TRUNCATE |
> STABLE | DEFAULT ]. [wallog]
>
> * Allow control over which tables are WAL-logged
>
> Allow tables to bypass WAL writes and just fsync() dirty pages on
> commit. To do this, only a single writer can modify the table, and
> writes must happen only on new pages. Readers can continue accessing
> the table. Another option is to avoid transaction logging entirely
> and truncate or drop the table on crash recovery. These should be
> implemented using ALTER TABLE, e.g. ALTER TABLE PERSISTENCE [ DROP |
> TRUNCATE | STABLE | DEFAULT ]. [wallog]
(previously we only did = and <> correctly). Also, allow row comparisons
with any operators that are in btree opclasses, not only those with these
specific names. This gets rid of a whole lot of indefensible assumptions
about the behavior of particular operators based on their names ... though
it's still true that IN and NOT IN expand to "= ANY". The patch adds a
RowCompareExpr expression node type, and makes some changes in the
representation of ANY/ALL/ROWCOMPARE SubLinks so that they can share code
with RowCompareExpr.
I have not yet done anything about making RowCompareExpr an indexable
operator, but will look at that soon.
initdb forced due to changes in stored rules.
* %Make row-wise comparisons work per SQL spec
Right now, '(a, b) < (1, 2)' is processed as 'a < 1 and b < 2', but
the SQL standard requires it to be processed as a column-by-column
comparison, so the proper comparison is '(a < 1) OR (a = 1 AND b < 2)'.
Fix example for day and hours interval subtraction for new computation
method.
Update interval examples to display zero seconds, which is our default.
Backpatch to 8.1.X.
Per my recent proposal. I ended up basing the implementation on the
existing mechanism for enforcing valid join orders of IN joins --- the
rules for valid outer-join orders are somewhat similar.
< * Allow star join optimizations
<
< While our bitmap scan allows multiple indexes to be joined to get
< to heap rows, a star joins allows multiple dimension _tables_ to
< be joined to index into a larger main fact table. The join is
< usually performed by either creating a cartesian product of all
< the dimmension tables and doing a single join on that product or
< using subselects to create bitmaps of each dimmension table match
< and merge the bitmaps to perform the join on the fact table. Some
< of these algorithms might be patented.
< * Flush cached query plans when the dependent objects change or
< when the cardinality of parameters changes dramatically
> * Flush cached query plans when the dependent objects change,
> when the cardinality of parameters changes dramatically, or
> when new ANALYZE statistics are available
Drake:
< and merge the bitmaps to perform the join on the fact table.
> and merge the bitmaps to perform the join on the fact table. Some
> of these algorithms might be patented.
* Allow star join optimizations
While our bitmap scan allows multiple indexes to be joined to get
to heap rows, a star joins allows multiple dimension _tables_ to
be joined to index into a larger main fact table. The join is
usually performed by either creating a cartesian product of all
the dimmension tables and doing a single join on that product or
using subselects to create bitmaps of each dimmension table match
and merge the bitmaps to perform the join on the fact table.
Bruce Momjian