WAL Log Data Block Size - Teradata Database

Teradata Database Design

Teradata Database
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WAL Log Data Block Size

When you know the maximum row length, double the value to calculate the size of your multirow data block definition in the JournalDBSize parameter of the DBS Control Record. For example, the JournalDBSize value should be greater or equal to twice the maximum row length.

The file system allocates any row that exceeds the current size of a multirow data block to a WAL log data block of its own.

Depending on the configuration of your system, Teradata Database builds its data blocks using either native 512 byte sectors or native 4KB sectors. Systems built on 512 byte sectors are referred to as unaligned configurations, while systems built on 4KB sectors are referred to as aligned configurations.

For details on the JournalDBSize parameter, see the DBS Control utility chapter in Utilities.