Is there any indexing technique available I can use when joining tables with a regular expression pattern in pgsql?
I know one method for indexing strings that will be matched with regular expression patterns, and that is using so called k-gram indexes. Indexing the string "kjartan" with k-gram index where k = 3 would create "kja", "jar", "art", "rta", "tan" as an index. Ofcourse it is hard to decide the size of k and I'm sure in many cases mulitple k values might be needed, depending on the situation. I have not done any major survey of available techniques, but I was hoping I could get some pointers here. I assume pgsql always uses nested loop join when joining relations which are joined with regular expression pattern? -- Kjartan Ásþórsson http://www.kjarri.net Tel: +46 (0)730 556705 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
