On Wed, Nov 09, 2005 at 10:18:35AM -0800, TJ O'Donnell wrote: > I like the new bitmap scans and I'm wondering if there is any way > I can utilize them for my bitmask column, defined as bit(1024). > I use this column as a sort of fingerprint to quickly scan my tables. > But it is a scan, not an index. I have not figured out a way to > index the bitmask column. Is there some way it can be used as > an index now that there are bitmap scans in 8.1? Note: the fact that they are called bitmaps indexes doesn't imply anything about the types used. The fact that you have a field already as a bitmap doesn't actually help. The operation still needs to be an indexable. However, bitmaps indexes does mean that a single query can use multiple indexes. So if you can split your contains into different parts of the string, the optimozier can combine them. Whether this is more efficient, who knows... Hope this helps, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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