Re: Netapps vs EMC -- db file scattered read

<jmourik_at_yahoo.com> wrote in message
news:1106214070.081684.277660_at_z14g2000cwz.googlegroups.com...
> Don't know if anybody here has seen this happening on NetApps storage.
>
> I ran query "select count(*) from jvmo_test;" on three of our
> databases, ids9i, nyisos (both on NetApp) and gmps (on EMC). The tables
> are all the same, build from the sam base table and then rows copied
> until there are 1,600,000...
> I don't understand why the wait times for NetApps are so much higher
> than for EMC. Take a look at these results:
>
> IDS9I - NetApps
>
> table info, blocksize = 8K:
> BYTES BLOCKS EXTENTS
> 351010816 42848 2678
>
> call count cpu elapsed disk query current
> rows
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> Parse 1 0.00 0.00 0 0 0
> 0
> Execute 1 0.00 0.00 0 0 0
> 0
> Fetch 2 6.08 53.41 42842 43115 0
> 1
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> total 4 6.08 53.41 42842 43115 0
> 1
>
> Elapsed times include waiting on following events:
> Event waited on Times Max. Wait Total Waited
> ------------------------------ Waited ---------- ------------
> SQL*Net message to client 2 0.00 0.00
> db file scattered read 2678 0.10 50.00
>
> NYISOS - NetApps
> table info, blocksize = 16K:
> BYTES BLOCKS EXTENTS
> 345112576 21064 2633
>
>
> call count cpu elapsed disk query current
> rows
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> Parse 1 0.00 0.00 0 0 0
> 0
> Execute 1 0.00 0.00 0 0 0
> 0
> Fetch 2 6.15 61.62 17628 21329 0
> 1
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> total 4 6.15 61.62 17628 21329 0
> 1
>
> Elapsed times include waiting on following events:
> Event waited on Times Max. Wait Total Waited
> ------------------------------ Waited ---------- ------------
> db file sequential read 1142 0.06 7.31
> db file scattered read 2286 0.09 52.29
>
>
> GMSP - EMC
> table info, blocksize = 8K:
> BYTES BLOCKS EXTENTS
> 348913664 42592 2662
>
> call count cpu elapsed disk query current
> rows
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> Parse 1 0.00 0.01 0 0 0
> 0
> Execute 1 0.00 0.00 0 0 0
> 0
> Fetch 2 6.77 6.95 42574 42587 273
> 1
> ------- ------ -------- ---------- ---------- ---------- ----------
> ----------
> total 4 6.77 6.96 42574 42587 273
> 1
>
> Elapsed times include waiting on following events:
> Event waited on Times Max. Wait Total Waited
> ------------------------------- Waited ---------- ------------
> SQL*Net message to client 2 0.00 0.00
> db file scattered read 2663 0.02 3.57
>
>
> EMC is more than 7 times faster than NetApps! db file scattered read is
> way too high for Netapps....
>
> Any ideas?
>
> Thanks for any info, jan

Is the EMC SAN and the NetApps NAS? Received on Thu Jan 20 2005 - 08:25:46 CST