> Who cares how effect of smaller space occupied by the record is called, > important thing is a result - size and certainly time for compression > and specially decompression. Elekt Labs RLE is faster then current one, because works on larger blocks (up ~4MB).
See performance results here: http://elektlabs.cz/fbrle/ I had new version with little better compression and speed, but it is marginal. > >> But back to original question. >> Is it right time to change record/fragment compression/encoding? > We are going to have soon TTG solution re. list of v.4 features. Can you provide more info about this, I miss this :( > If we decide not to change ODS major in v.4 commit of LZ4 appears > suspicious. I.e. I think you should wait a bit. LZ4 has only marginal effect on my DBs. I'm using short records (after RLE about 30 bytes). But on large record, mainly texts, the benefits is significant. > > What is also interesting - how does your compression work with records > other than containing single varachar(8000)? Some mix of > integrs/floats/strings? Yes. As I wrote, Elekt Labs RLE works well up 4MB record size. It is mean, 4MB of zeroes is packed into 3 bytes. > Personally I (after my own experiments with LZ4 for wire compression) > believe that it should fit well for records compression, but it's always > good to provide more facts. What is looking strange for me is that LZ4 Because LZ4 has limit 1:255, current RLE has limit 1:64. VARCHAR(8000) in UTF8 has 32k. When is null, Elekt Labs RLE will pack into 3 bytes, LZ4 into ~125 + overhead, current RLE into 500. > works better when used over RLE. As far as I understand it's algorithm > is should do it's job fine without RLE. Results of comparisons for data > mix is very interesting. > > Last but not least - did you run our test suites with your patch? Only our internal tests + we was using in my company for a while without problems. We stops, because I need testing 2.5.4 and 2.5.5 before deploy to customers. May be Pavel Cisar did a tests, good time to ask him. Slavek ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
