selectivity functions and make the r-tree operators use them. The
estimation functions themselves are just stubs, unfortunately, but
perhaps someday someone will make them compute realistic estimates.
Change pg_am so that the optimizer can reliably tell the difference
between ordered and unordered indexes --- before it would think that
an r-tree index can be scanned in '<<' order, which is not right AFAIK.
Repair broken negator links for network_sup and related ops.
Initdb forced. This might be my last initdb force for 7.0 ... hope so
anyway ...
accesses versus sequential accesses, a (very crude) estimate of the
effects of caching on random page accesses, and cost to evaluate WHERE-
clause expressions. Export critical parameters for this model as SET
variables. Also, create SET variables for the planner's enable flags
(enable_seqscan, enable_indexscan, etc) so that these can be controlled
more conveniently than via PGOPTIONS.
Planner now estimates both startup cost (cost before retrieving
first tuple) and total cost of each path, so it can optimize queries
with LIMIT on a reasonable basis by interpolating between these costs.
Same facility is a win for EXISTS(...) subqueries and some other cases.
Redesign pathkey representation to achieve a major speedup in planning
(I saw as much as 5X on a 10-way join); also minor changes in planner
to reduce memory consumption by recycling discarded Path nodes and
not constructing unnecessary lists.
Minor cleanups to display more-plausible costs in some cases in
EXPLAIN output.
Initdb forced by change in interface to index cost estimation
functions.
The PostgreSQL's to_char() is very compatible with Oracle's to_char
now. I hope that to_char's 3000 rows of source is without bugs, but
will good if anyone test it, for me it works very well :-)
Karel
----------------------------------------------------------------------
Karel Zak <zakkr@zf.jcu.cz> http://home.zf.jcu.cz/~zakkr/
regression tests so I prepared a set of expected
files to make things look OK.
There's also a file to account for minor variations
in the geopmetry output and a resultmap patch to
pull them all together.
With these changes PostgreSQL, from CVS, builds and
regression tests (runcheck) cleanly.
Keith Parks.
Initdb help correction
Changed end/abort to commit/rollback and changed related notices
Commented out way old printing functions in libpq
Fixed a typo in alter table / alter column
SELECT DISTINCT ON (expr [, expr ...]) targetlist ...
and there is a check to make sure that the user didn't specify an ORDER BY
that's incompatible with the DISTINCT operation.
Reimplement nodeUnique and nodeGroup to use the proper datatype-specific
equality function for each column being compared --- they used to do
bitwise comparisons or convert the data to text strings and strcmp().
(To add insult to injury, they'd look up the conversion functions once
for each tuple...) Parse/plan representation of DISTINCT is now a list
of SortClause nodes.
initdb forced by querytree change...
family functions. Contain:
conversion from a datetype to formatted text:
to_char( datetime, text)
to_char( timestamp, text)
to_char( int4, text)
to_char( int8, text)
to_char( float4, text)
to_char( float8, text)
to_char( numeric, text)
vice versa:
to_date ( text, text)
to_datetime ( text, text)
to_timestamp ( text, text)
to_number ( text, text) (convert to numeric)
PostgreSQL to_char is very compatible with Oracle's to_char(), but not
total exactly (now). Small differentions are in number formating. It will
fix in next to_char() version.
! If will this patch aplly to the main tree, must be delete the current
to_char version in contrib (directory "dateformat" and note in contrib's
README), this patch not erase it (sorry Bruce).
The patch patching files:
doc/src/sgml/func.sgml
^^^^^^^^
Hmm, I'm not sure if my English... :( Check it anyone (volunteer)?
Thomas, it is right? SGML is not my primary lang and compile
the current PG docs tree is very happy job (hard variables setting in
docs/sgml/Makefile --> HSTYLE= /home/users/t/thomas/.... :-)
What add any definition to global configure.in and set Makefiles in docs
tree via ./configure?
src/backend/utils/adt/Makefile
src/backend/utils/adt/formatting.c
src/include/catalog/pg_proc.h
src/include/utils/formatting.h
Karel Zak <zakkr@zf.jcu.cz> http://home.zf.jcu.cz/~zakkr/
(ie, WHERE x > lowbound AND x < highbound). It's not very bright yet
but it does something useful. Also, rename intltsel/intgtsel to
scalarltsel/scalargtsel to reflect usage better. Extend convert_to_scalar
to do something a little bit useful with string data types. Still need
to make it do something with date/time datatypes, but I'll wait for
Thomas's datetime unification dust to settle first. Eventually the
routine ought not have any type-specific knowledge at all; it ought to
be calling a type-dependent routine found via a pg_type column; but
that's a task for another day.
pghackers discussion of 5-Jan-2000. The amopselect and amopnpages
estimators are gone, and in their place is a per-AM amcostestimate
procedure (linked to from pg_am, not pg_amop).
Tom Lane
Thomas G. Lockhart
Bruce Momjian
Peter Eisentraut