RE: Very slow metadata extraction?
"R.W. Shore" <[email protected]>
| Newsgroups | gmane.comp.db.mckoi |
|---|---|
| Message-ID | <[email protected]> |
I may have miscommunicated. The results below are from the 'select * from SYS_INFO.sUSRTableColumns' that you wanted me to run. I don't know why it took so long on the client - I'm using a wireless net that isn't THAT slow. To answer your question directly: in the code that I've since rewritten, the getColumns() specified a non-wildcarded catalog, schema, and table, and it specified "%" as the column patern. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tobias Downer Sent: Monday, November 29, 2004 7:54 PM To: [email protected] Subject: Re: Very slow metadata extraction? What were the filters you were applying to 'getColumns'? It looks obvious from this information that the filtering is the bottleneck. Thanks, Toby. R.W. Shore wrote: > Re select: > o Command started spewing data back in maybe 3 seconds. > o Total rows returned: 49447 > o Execution time on the client host: 20.5 minutes. This used a command-line > SQL processor that dumps results to System.out. I redirected the output to > file to avoid the time on the client side required to scroll the command > window. CPU on the client side was around 50%. CPU on the database host was > loafing - under 10%. > o Execution time on the DB host: 12 seconds. This used the Mckoi JDBC query > tool. It returned the same number of rows, just a LOT faster. > > BTW, I've rewritten the code that cause the original message. I now do one > call to getColumns() and filter out the desired tables in the code, rather > than doing a getColumns() call for each of the desired tables. Total > execution time went down from 5 hours (est) to 3 minutes (measured). --------------------------------------------------------------- Mckoi SQL Database mailing list http://www.mckoi.com/database/ To unsubscribe, send a message to [email protected] --------------------------------------------------------------- Mckoi SQL Database mailing list http://www.mckoi.com/database/ To unsubscribe, send a message to [email protected]