Tom Lane wrote: > Bruce Momjian <[EMAIL PROTECTED]> writes: > > <para> > > ! Because of the limited utility of hash indexes, a B-tree index > > ! should generally be preferred over a hash index. We do not have > > ! sufficient evidence that hash indexes are actually faster than > > ! B-trees even for <literal>=</literal> comparisons. Moreover, > > ! hash indexes require coarser locks; see <xref > > ! linkend="locking-indexes">. > > </para> > > </note> > > </para> > > --- 181,189 ---- > > </synopsis> > > <note> > > <para> > > ! Testing has shown that hash indexes are slower than btree indexes, > > ! and the size and build time for hash indexes is much worse. For > > ! these reasons, hash index use is discouraged. > > This change strikes me as a step backwards. The existing wording tells > the truth; the proposed revision removes the facts in favor of a blanket > assertion that is demonstrably false.
OK, which part of is "demonstrably false"? I think the old "should generally be preferred" is too vague. No one has come up with a case where hash has shown to be faster, and a lot of cases where it is slower. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026 ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
