On 4th of December Peter Eisentraut committed patch by Pavel Stehule (with Peters tweaks) which adds default values for function arguments:
Default values for function arguments Pavel Stehule, with some tweaks by Peter Eisentraut
Continue reading Waiting for 8.4 – Default values for function arguments + integer in any base
Yeah. This one patch alone is worth upgrading to 8.4.
On 3rd of December Heikki Linnakangas committed his patch. Commit message:
Introduce visibility map. The visibility map is a bitmap with one bit per heap page, where a set bit indicates that all tuples on the page are visible to all transactions, and the page therefore doesn't need vacuuming. It is stored in a new relation fork. Lazy vacuum uses the visibility map to skip pages that don't need vacuuming. Vacuum is also responsible for setting the bits in the map. In the future, this can hopefully be used to implement index-only-scans, but we can't currently guarantee that the visibility map is always 100% up-to-date. In addition to the visibility map, there's a new PD_ALL_VISIBLE flag on each heap page, also indicating that all tuples on the page are visible to all transactions. It's important that this flag is kept up-to-date. It is also used to skip visibility tests in sequential scans, which gives a small performance gain on seqscans.
On Thursday, 20th of November, Peter Eisentraut committed his own patch, which adds new command to PostgreSQL: TABLE.
While this command doesn't do anything that wasn't available earlier, it's worth mentioning, as it's one of patches that make PostgreSQL compatible with SQL:2008.
Basically new command “TABLE" acts like an alias to ‘SELECT * FROM':
On 19th of November Tom Lane committed patch by Takahiro Itagaki which does:
Add auto-explain contrib module for automatic logging of the plans of slow-running queries.
Finally, we got very important addons to PostgreSQL, which help with dealing with arrays.
It solves a lot of problems, which were usually solved with standard cookbook code, which was in faqs, blog posts and number of examples on irc.
Continue reading Waiting for 8.4 – array aggregate and array unpacker
On 3rd of November Andrew Dunstan committed his patch which adds new function to PostgreSQL – suppress_redundant_updates_trigger().
This function is not for using in selects, but it can help you tremendously if your database access matches certain pattern.
Continue reading Waiting for 8.4 – suppress_redundant_updates_trigger
In PostgreSQL 8.2, we got “RETURNING" clause in INSERT/UPDATE/DELETE queries.
Unfortunately it could not be used as source of rows for anything in sql.
INSERT INTO table_backup DELETE FROM TABLE WHERE ... returning *;
Well, it's still not possible, but it is a one step closer, thanks to patch written and committed by Tom Lane on 31st of October:
Allow SQL-LANGUAGE functions TO RETURN the output OF an INSERT/UPDATE/DELETE RETURNING clause, NOT just a SELECT AS formerly. A side effect OF this patch IS that WHEN a set-returning SQL FUNCTION IS used IN a FROM clause, performance IS improved because the output IS collected INTO a tuplestore WITHIN the FUNCTION, rather than USING the less efficient value-per-CALL mechanism.
On 28th of October Tom Lane committed his patch that changes some internals of functions, but it also adds interesting capability.
Continue reading Waiting for 8.4 – pl/* srf functions in selects
On 4th of September Tom Lane committed another great patch. This one is very large, and even after applying – it's has some rough edges. There will be need for additional patches to make the functionality fully robust, but the fact that it got committed means that it will be available in final 8.4.
What does it do?
Continue reading Waiting for 8.4 – Common Table Expressions (WITH queries)
On 30th of September, Heikki Linnakangas committed his patch that changes FSM:
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.