4 Commits (d66a922f9247ceaa6caed9b51ce686f12e280091)

Author	SHA1	Message	Date
Tom Lane	eb67623c96	Mark some contrib modules as "trusted". ... This allows these modules to be installed into a database without superuser privileges (assuming that the DBA or sysadmin has installed the module's files in the expected place). You only need CREATE privilege on the current database, which by default would be available to the database owner. The following modules are marked trusted: btree_gin btree_gist citext cube dict_int earthdistance fuzzystrmatch hstore hstore_plperl intarray isn jsonb_plperl lo ltree pg_trgm pgcrypto seg tablefunc tcn tsm_system_rows tsm_system_time unaccent uuid-ossp In the future we might mark some more modules trusted, but there seems to be no debate about these, and on the whole it seems wise to be conservative with use of this feature to start out with. Discussion: https://postgr.es/m/32315.1580326876@sss.pgh.pa.us	6 years ago
Tom Lane	7d08ce286c	Distinguish selectivity of < from <= and > from >=. ... Historically, the selectivity functions have simply not distinguished < from <=, or > from >=, arguing that the fraction of the population that satisfies the "=" aspect can be considered to be vanishingly small, if the comparison value isn't any of the most-common-values for the variable. (If it is, the code path that executes the operator against each MCV will take care of things properly.) But that isn't really true unless we're dealing with a continuum of variable values, and in practice we seldom are. If "x = const" would estimate a nonzero number of rows for a given const value, then it follows that we ought to estimate different numbers of rows for "x < const" and "x <= const", even if the const is not one of the MCVs. Handling this more honestly makes a significant difference in edge cases, such as the estimate for a tight range (x BETWEEN y AND z where y and z are close together). Hence, split scalarltsel into scalarltsel/scalarlesel, and similarly split scalargtsel into scalargtsel/scalargesel. Adjust <= and >= operator definitions to reference the new selectivity functions. Improve the core ineq_histogram_selectivity() function to make a correction for equality. (Along the way, I learned quite a bit about exactly why that function gives good answers, which I tried to memorialize in improved comments.) The corresponding join selectivity functions were, and remain, just stubs. But I chose to split them similarly, to avoid confusion and to prevent the need for doing this exercise again if someone ever makes them less stubby. In passing, change ineq_histogram_selectivity's clamp for extreme probability estimates so that it varies depending on the histogram size, instead of being hardwired at 0.0001. With the default histogram size of 100 entries, you still get the old clamp value, but bigger histograms should allow us to put more faith in edge values. Tom Lane, reviewed by Aleksander Alekseev and Kuntal Ghosh Discussion: https://postgr.es/m/12232.1499140410@sss.pgh.pa.us	8 years ago
Robert Haas	b79b8d8f55	Update isn extension for parallel query. ... All functions provided by this extension are PARALLEL SAFE. Andreas Karlsson	10 years ago
Tom Lane	629b3af27d	Convert contrib modules to use the extension facility. ... This isn't fully tested as yet, in particular I'm not sure that the "foo--unpackaged--1.0.sql" scripts are OK. But it's time to get some buildfarm cycles on it. sepgsql is not converted to an extension, mainly because it seems to require a very nonstandard installation process. Dimitri Fontaine and Tom Lane	15 years ago