Sybase 12.4.2 - Manual (Page 125)

CHAPTER 3 Working with Database Objects
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Space requirements
for IQ Stores The amount of data, and the number and types of indexes you create, determine
how much space you need in your IQ database. If you run out of space when
loading or inserting into a database, Adaptive Server IQ prompts you to create
another dbspace, and then continues the operation after you add the dbspace.
Space requirements
for Temporary Stores In addition to any temporary tables you define explicitly, Adaptive Server IQ
uses the Temporary Store as a temporary result space for sorts, hashes, and
bitmaps during loads and deletions. The types of queries issued, the degree of
concurrent use, and the size of your data, all determine how much space you
need for your Temporary Store.
Estimating space and dbspaces required
To avoid difficulties when a database or a particular dbspace is full, you should
estimate the amount of space and dbspaces you need before you create the
database and the objects in it. Adaptive Server IQ provides stored procedures
that you can run to estimate how much space and how many dbspaces your
databases will require. See the Adaptive Server IQ Reference Manual for
syntax and usage notes for each procedure.
Running the procedures in the sequence that follows can help you avoid
running out of space for your objects.
1 Run the stored procedure sp_iqestspace to estimate the amount of space
you will need to create a database, based on the number of rows in the
underlying database tables. Run the procedure once for each table that you
plan to create, as follows:
sp_iqestspace table_name, rows[, iqpagesize]
The amount of space needed by each table is returned as “RAW DATA
index_size”.
2 Add totals under “RAW DATA index_size” for all tables together.
3 Run the stored procedure sp_iqestjoin to estimate the amount of additional
space required to create join indexes on tables that you want to join
frequently. Run the procedure once for each pair of tables, as follows:
sp_iqestjoin table1, table1rows, table2, table2rows
[, relation] [,iqpagesize] ...
sp_iqestjoin suggests different index sizes depending on your queries.