On 8/3/06, hansell baran <hansellb@xxxxxxxxx> wrote:
Hi. I'm new at using PostgreSQL. Where I work, all databases were built with MS Access. The Access files are hosted by computers with Windows 2000 and Windows XP. A new server is on its way and only Open Source Software is going to be installed. The OS is going to be SUSE Linux 10.1 and we are making comparisons between MySQL, PostgreSQL and MS Access. We installed MySQL and PostgreSQL on both SUSE and Windows XP (MySQL & PostgreSQL DO NOT run at the same time)(There is one HDD for Windows and one for Linux) The "Test Server" in which we install the DBMS has the following characteristics: CPU speed = 1.3 GHz RAM = 512 MB HDD = 40 GB The biggest table has 544371 rows(tuples?) with 55 rows. All fields are float8. Only 1 is varchar(255) and 1 timestamp. We query the MS Access databases through Visual Basic Programs and ODBC Drivers. We made a Visual Basic program that uses ADO to connect to ALL three DBMS using ODBC drivers. When we run the following query "SELECT * FROM big_table", we get the following resutls: MS Access - Execution time ~ 51 seconds (Depending on the client machine, it can go as low as 20 seconds) - Network Utilization ~ 80 Mbps (According to Windows Task Manager) MySQL 5.0 (under Windows) - Execution time ~ 630 seconds - Network Utilization ~ 8 Mbps PostgreSQL 8.1 (under Windows) - Execution time ~ 290 seconds) - Network Utilization ~ 13 Mbps MS Access (under Linux. MS Access files are in the Linux computer which has the SAMBA server running. The client computer has a mapped network drive that conects to the Linux files.) - Execution time ~ 55 seconds (Depending on the client machine, it can go as low as 20 seconds) - Network Utilization ~ 76 Mbps (According to Windows Task Manager) MySQL 5.0(under Linux) - Execution time ~ 440 seconds - Network Utilization ~ 11 Mbps PostgreSQL 8.1(under Linux) - Execution time ~ 180 seconds) - Network Utilization ~ 18 Mbps Very different results are obtained if a the query "SELECT * from big_table ORDER BY "some_column"". In this scenario
you have to be careful comparing access to mysql/postgresql in this way because the architecture is different...these results are a bit misleading. access can do some optimization tricks on very simple queries, especially select * from bigtable becuase the result does not have to be fully materialized and returned to the client.
PostgreSQL is faster than MS Access or MySQL by more than 100 seconds. We have run many other queries (not complex, at most nesting of 5 inner joins) and MS Access is always faster. We have seen
i find this really hard to believe. is your postgresql database properly indexed and did you run analyze? do the standard -performance thing, run the query in with explain analyze: explain anaylze 5_table_join_query and post the results to this list. merlin
