Luke Lonergan wrote: > Tom, > > > > ... and instead, define some new behavior that will soon be considered > > broken legacy code itself? > > I'll not argue further about whether to have a separate LOAD command. > That's not as important as fixing the performance issues in the data load > path in PostgreSQL to me. > > However, I find it compelling that the underlying problem confronting high > performance data loading in the engine is the slow parse code in psql/copy, > etc., and not the WAL or other issues. Next on the list are huge gains from > removing things like repetitive calls to strlen(TZ) in the attribute > conversion code.
Yep, we would _love_ those improvements. > > There isn't any demand for changing the semantics of COPY, as far as > > I've noticed. If we can make it faster with the same semantics that's > > great, but I'm not in favor of inventing an alternate that does almost > > the same thing but (eg) breaks backslash handling in the name of speed. > > A 540% increase in parsing speed while performing substantially the same > logic is what the patch accomplishes. The patch is now available on > pgsql-patches. In this case the speed did not come from breaking backslash > handling, but rather from using faster processing for escape processing and > delimiter parsing. We *could* recreate identical escape semantics to COPY > at nearly the same speed, but frankly we're puzzled as to why character > sequences with "\" automatically imply escape processing. I am confused why you are confused. :-) > We've found that there are many cases where more sophisticated escape > processing options are necessary, including multi-byte delimiters and escape > sequences, and the default use of "\" for escaping breaks many data load > cases. Uh, how do you do the escapes if you don't double the escape character on input so you can distinguish a literal escape from one use to mark special data like a literal delimiter or a null? -- 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]
