JDBC Query performance
От | Postgres mailing lists |
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Тема | JDBC Query performance |
Дата | |
Msg-id | 003101be711c$d09ff740$64ba01cc@earthlink.net обсуждение исходный текст |
Список | pgsql-interfaces |
Hello, I've been using the JDBC driver that came with postgres 6.4.2. It seems to work pretty well, but noticed that the query performance seemed very low. For example, I have a table with about 1200 rows, 20 columns. I'm not using indexes yet. I do a query using psql like "select * from mytable" and pipe it to a file. It takes about a second or so to complete and I notice the CPU idle time goes to maybe 50%. Pretty fast. Doing the same query using the JDBC driver takes the CPU idle to 0% for about 90 seconds, then finally returns. A code fragment... String sql = "select * from mytable"; Connection conn = get_con(); // uses a DbConnectionBroker class. Performs the same with or without this class. stmt = conn.createStatement(); rs = stmt.executeQuery(sql); more = rs.next(); Trace("Finished Query. Filling Vector." ); while (more) { count ++; vector.addElement((new Long(rs.getLong("ID")).toString())); vector.addElement(rs.getString("Name")); etc... more = rs.next(); } rs.close(); stmt.close(); ... The executeQuery(sql) statement takes about 90 secs, then I see the Trace output, then the vector operations take about 10-15 secs. I suppose I can live with the Vector op time, if there is no more effecient way of getting query results, (I haven't really looked into it), but 90 secs for executing the query seems unreasonable. Anyone else experience this type of thing? Thanks in Advance. Rich.
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