< * Experiment with multi-threaded backend better resource utilization
<
< This would allow a single query to make use of multiple CPU's or
< multiple I/O channels simultaneously. One idea is to create a
< background reader that can pre-fetch sequential and index scan
< pages needed by other backends. This could be expanded to allow
< concurrent reads from multiple devices in a partitioned table.
<
> * Experiment with multi-threaded backend better resource utilization
>
> This would allow a single query to make use of multiple CPU's or
> multiple I/O channels simultaneously. One idea is to create a
> background reader that can pre-fetch sequential and index scan
> pages needed by other backends. This could be expanded to allow
> concurrent reads from multiple devices in a partitioned table.
* Consider having the background writer update the transaction status
hint bits before writing out the page
Implementing this requires the background writer to have access to system
catalogs and the transaction status log.
<
< * Allow free-behind capability for large sequential scans to avoid
< kernel cache spoiling
<
< Posix_fadvise() can control both sequential/random file caching and
< free-behind behavior, but it is unclear how the setting affects other
< backends that also have the file open, and the feature is not supported
< on all operating systems.
< o -Allow commenting of variables in postgresql.conf to restore them
< to defaults
< o -Add a GUC variable to control the tablespace for temporary objects
< and sort files
< Monitoring
< ==========
<
< * -Allow server log information to be output as CSV format
< * -Add ability to monitor the use of temporary sort files
< * -Allow user-defined types to accept 'typmod' parameters
<
< http://archives.postgresql.org/pgsql-hackers/2005-08/msg01142.php
< http://archives.postgresql.org/pgsql-hackers/2005-09/msg00012.php
< http://archives.postgresql.org/pgsql-hackers/2006-08/msg00149.php
<
< * -Add Globally/Universally Unique Identifier (GUID/UUID)
<
< http://archives.postgresql.org/pgsql-patches/2006-09/msg00209.php
< http://archives.postgresql.org/pgsql-general/2007-01/msg00853.php
<
< * -Support a data type with specific enumerated values (ENUM)
< o -Add support for arrays of complex types
< o -Make 64-bit version of the MONEY data type
< * -Add ISO day of week format 'ID' to to_char() where Monday = 1
< * -Add a field 'isoyear' to extract(), based on the ISO week
< * -Add RESET SESSION command to reset all session state
< o -Make CLUSTER preserve recently-dead tuples per MVCC requirements
< o -Add more logical syntax CLUSTER table USING index;
< support current syntax for backward compatibility
< o -Allow UPDATE/DELETE WHERE CURRENT OF cursor
< o -Add support for MOVE cursors
< o -Allow PL/PythonU to return boolean rather than 1/0
< o -Allow psql \pset boolean variables to set to fixed values, rather
< than toggle
< o -Add -f to pg_dumpall
< Dependency Checking
< ===================
<
< * -Flush cached query plans when the dependent objects change or
< when new ANALYZE statistics are available
< * -Track dependencies in function bodies and recompile/invalidate
< * -Invalidate prepared queries, like INSERT, when the table definition
< is altered
<
< * -Allow use of indexes to search for NULLs
< * -Allow the creation of indexes with mixed ascending/descending
< specifiers
< * -Reduce checkpoint performance degredation by forcing data to disk
< more evenly
< * -Allow sequential scans to take advantage of other concurrent
< sequential scans, also called "Synchronised Scanning"
< * -Consider shrinking expired tuples to just their headers
< * -Allow heap reuse of UPDATEd rows if no indexed columns are changed,
< and old and new versions are on the same heap page
< * -Reduce XID consumption of read-only queries
< o -Turn on by default
< o -Allow multiple vacuums so large tables do not starve small
< tables
< * -Allow the pg_xlog directory location to be specified during initdb
< with a symlink back to the /data location
< * -Allow buffered WAL writes and fsync
< * -Allow ORDER BY ... LIMIT # to select high/low value without sort or
< index using a sequential scan for highest/lowest values
< * -Merge xmin/xmax/cmin/cmax back into three header fields
< o -Support a smaller header for short variable-length fields
< * -Move NAMEDATALEN from postgres_ext.h to pg_config_manual.h
< * -Fix problem with excessive logging during SSL disconnection
<
< http://archives.postgresql.org/pgsql-bugs/2006-12/msg00122.php
< http://archives.postgresql.org/pgsql-bugs/2007-05/msg00065.php
<
< o -Add long file support for binary pg_dump output
< * Prevent long-lived temporary tables from causing frozen-Xid advancement
> * Prevent long-lived temporary tables from causing frozen-xid advancement
>
> The problem is that autovacuum cannot vacuum them to set frozen xids;
> only the session that created them can do that.
>
>
>
< o Prevent COMMENT ON dbname from issuing a warning when loading
< into a database with a different name, perhaps using COMMENT ON
< CURRENT DATABASE
> o Change pg_dump so that a comment on the dumped database is
> applied to the loaded database, even if the database has a
> different name. This will require new backend syntax, perhaps
> COMMENT ON CURRENT DATABASE.
< o Allow COMMENT ON dbname to work when loading into a database
< with a different name, perhaps using COMMENT ON CURRENT
< DATABASE
> o Prevent COMMENT ON dbname from issuing a warning when loading
> into a database with a different name, perhaps using COMMENT ON
> CURRENT DATABASE
> * -Consider shrinking expired tuples to just their headers
> * -Allow heap reuse of UPDATEd rows if no indexed columns are changed,
> and old and new versions are on the same heap page
Not needed anymore:
< * Reuse index tuples that point to heap tuples that are not visible to
< anyone?
< o Allow UPDATE/DELETE WHERE CURRENT OF cursor
<
< This requires using the row ctid to map cursor rows back to the
< original heap row. This become more complicated if WITH HOLD cursors
< are to be supported because WITH HOLD cursors have a copy of the row
< and no FOR UPDATE lock.
< http://archives.postgresql.org/pgsql-hackers/2007-01/msg01014.php
<
> o -Allow UPDATE/DELETE WHERE CURRENT OF cursor
o -Add a GUC variable to control the tablespace for temporary objects
and sort files
<
< It could start with a random tablespace from a supplied list and
< cycle through the list.
<
< * Allow free-behind capability for large sequential scans, perhaps using
< posix_fadvise()
> * Allow free-behind capability for large sequential scans to avoid
> kernel cache spoiling
scan-resistant:
<
< * Allow free-behind capability for large sequential scans, perhaps using
< posix_fadvise()
<
< Posix_fadvise() can control both sequential/random file caching and
< free-behind behavior, but it is unclear how the setting affects other
< backends that also have the file open, and the feature is not supported
< on all operating systems.
< * Consider allowing 64-bit integers to be passed by value on 64-bit
< platforms
> * Consider allowing 64-bit integers and floats to be passed by value on
> 64-bit platforms
>
> Also change 32-bit floats (float4) to be passed by value at the same
> time.
>
* Improve speed with indexes
For large table adjustments during VACUUM FULL, it is faster to cluster
or reindex rather than update the index. Also, index updates can bloat
the index.
>
> * Implement the SQL standard mechanism whereby REVOKE ROLE revokes only
> the privilege granted by the invoking role, and not those granted
> by other roles