RE: $dbh-{RowCacheSize} = 1000
Loo, Peter # PHX wrote: Hi, Can someone please tell me what the size is when I set it to 1000? Is it one meg? It's $your_query_row_size * 1000. It's not a byte size, it's a number of rows. Regards, Philip
RE: $dbh-{RowCacheSize} = 1000
Loo, Peter # PHX [mailto:[EMAIL PROTECTED] wrote: Sent: Thursday, August 31, 2006 5:17 PM To: DBI-Users Subject: $dbh-{RowCacheSize} = 1000 Hi, Can someone please tell me what the size is when I set it to 1000? Is it one meg? perldoc DBI: RowCacheSize (integer) A hint to the driver indicating the size of the local row cache that the application would like the driver to use for future SELECT statements. If a row cache is not implemented, then setting RowCacheSize is ignored and getting the value returns undef. Some RowCacheSize values have special meaning, as follows: 0 - Automatically determine a reasonable cache size for each SELECT 1 - Disable the local row cache 1 - Cache this many rows 0 - Cache as many rows that will fit into this much memory for each SELECT. Note that large cache sizes may require a very large amount of memory (cached rows * maximum size of row). Also, a large cache will cause a longer delay not only for the first fetch, but also whenever the cache needs refilling. See also the RowsInCache statement handle attribute.
RE: $dbh-{RowCacheSize} = 1000
Hi All, What would you recommend I set this option to if I am sending all the SELECTed rows to a named pipe? Peter -Original Message- From: Ronald J Kimball [mailto:[EMAIL PROTECTED] Sent: Thursday, August 31, 2006 2:23 PM To: Loo, Peter # PHX; DBI-Users Subject: RE: $dbh-{RowCacheSize} = 1000 Loo, Peter # PHX [mailto:[EMAIL PROTECTED] wrote: Sent: Thursday, August 31, 2006 5:17 PM To: DBI-Users Subject: $dbh-{RowCacheSize} = 1000 Hi, Can someone please tell me what the size is when I set it to 1000? Is it one meg? perldoc DBI: RowCacheSize (integer) A hint to the driver indicating the size of the local row cache that the application would like the driver to use for future SELECT statements. If a row cache is not implemented, then setting RowCacheSize is ignored and getting the value returns undef. Some RowCacheSize values have special meaning, as follows: 0 - Automatically determine a reasonable cache size for each SELECT 1 - Disable the local row cache 1 - Cache this many rows 0 - Cache as many rows that will fit into this much memory for each SELECT. Note that large cache sizes may require a very large amount of memory (cached rows * maximum size of row). Also, a large cache will cause a longer delay not only for the first fetch, but also whenever the cache needs refilling. See also the RowsInCache statement handle attribute. This E-mail message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply E-mail, and destroy all copies of the original message.
RE: $dbh-{RowCacheSize} = 1000
Loo, Peter # PHX wrote: RowCacheSize (integer) What would you recommend I set this option to if I am sending all the SELECTed rows to a named pipe? I'd recommend you leave it alone, unless your database roundtrips are really expensive. And if they are, the only thing that can tell you what the best value would be is to benchmark different settings. It will only help if the program on the other end of the named pipe can accept data faster than you can send it. Philip
RE: $dbh-{RowCacheSize} = 1000
I would expect a C program to be able to write to a file faster than any database loader could load data. From: Loo, Peter # PHX [mailto:[EMAIL PROTECTED] Sent: Thu 8/31/2006 5:49 PM To: Garrett, Philip (MAN-Corporate); DBI-Users Subject: RE: $dbh-{RowCacheSize} = 1000 The reason I asked the question is that the Pro*C program appears to be writing the output to a file faster than my Perl program can write to the named pipe. The other end of the named pipe is a native database utility similar to the sqlldr (nzload). I don't know where the bottle neck is so I might have to break up the program into to separate parts. Have Perl dump the table to a file then feed the file using nzload and calculate the total time for each step. Peter -Original Message- From: Garrett, Philip (MAN-Corporate) [mailto:[EMAIL PROTECTED] Sent: Thursday, August 31, 2006 2:44 PM To: DBI-Users Subject: RE: $dbh-{RowCacheSize} = 1000 Loo, Peter # PHX wrote: RowCacheSize (integer) What would you recommend I set this option to if I am sending all the SELECTed rows to a named pipe? I'd recommend you leave it alone, unless your database roundtrips are really expensive. And if they are, the only thing that can tell you what the best value would be is to benchmark different settings. It will only help if the program on the other end of the named pipe can accept data faster than you can send it. Philip This E-mail message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply E-mail, and destroy all copies of the original message.