Modifying large tables in OpenIngres

>Subject: VLDB question
>From: Dillons Bookstore 
>Date: 26 Apr 1997 13:59:05 GMT
>Message-ID: <5jt1n9$mjm$1@sys10.cambridge.uk.psi.net>
>
>Anyone modified 20G or larger table recently in 6.4 or OpenIngres 1.2?
>How long does it take?
>
>derekw @dillons.co.uk

First, it is impossible to have a 20 GB Ingres table due to the current
architecture.  Due to the bitmapping of the Ingres TID, table size is
limited to 2^23 pages, or 16 GB.  This is true for Ingres 5/6, and also
for OpenIngres 1.x. OpenIngres 2.x is supposed to remove this limitation
(in addition to having other VLDB support).

Table modification time is mainly dependent on the performance of the I/O
subsystem of the machine being used.  Faster disks and controllers mean
less time to modify a table.  In addition, using multi-location tables and
multi-location sorting can also improve modification performance (due to
better distribution of I/O).  Table structure also has an impact on
modification performance.

OpenIngres has the ability to concurrently create secondary indexes.  This
can provide a significant benefit on large tables having more than one
secondary index.

The best thing to do is to benchmark table modification with various
configurations.  Monitor the OS and look for bottlenecks while the
modification is in progress.


Chip Nickolett           ChipN@Comp-Soln.com
Comprehensive Consulting Solutions, Inc.   (www.Comp-Soln.com)
Phone:  262-544-9954     Fax:  262-544-1236
Ingres Q & A
To William's Home Page
Email William