6.20 Estimating the size of an unload file

This section describes how to estimate the size of the unload file that is output when the adbreorgsystemdata command is executed. The size of an unload file is determined by the usage of system table (base table) to be reorganized.

Use the following formula to determine the size of an unload file (UNLDFILESIZE).

Formula (kilobytes)

Explanation of variables

ROWSIZE

Data length of one row in an unload file (bytes)

This value differs depending on the system table (base table). See the following table to determine the value.

Table 6‒27: Row data length of the unload file for each system table (base table)

No.	system table (base table)	Data length of one row in an unload file (bytes)
1	STATUS_TABLES table	417
2	STATUS_COLUMNS table	32,721
3	STATUS_INDEXES table	472
4	STATUS_CHUNKS table	1,436
5	STATUS_SYNONYM_DICTIONARIES table	2,237

ROWNUM

Number of rows in the system table (base table)

Obtain the number of rows in the reorganization-target system table (base table) by executing an SQL statement. For details, see (2) Checking the storage efficiency of a system table (base table) in 11.17.5 Checking the status and amount of use of system tables.

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