PFC wrote: > > There's a great deal about this in the list archives (probably more in > > pgsql-hackers than in -performance). Most of the current interest has > > to do with building in-memory bitmaps on the fly, as a way of decoupling > > index and heap scan processing. Which is not quite what you're talking > > about but should be pretty effective for low-cardinality cases. In > > particular it'd allow AND and OR combination of multiple indexes, which > > we do poorly or not at all at the moment. > > Is this called a star join ? > > It would also allow to access the data pages in a more sequential order > > if the rows are not required to be retrieved in index order, which would > potentially be a large speedup for index scans concerning more than the > usual very small percentage of rows in a table : if several rows to be > retrieved are on the same page, it would visit this page only once.
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Please see the TODO list for a summary of previous discussions and directions. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
