16.20 - CHECKSUM - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Syntax and Examples

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Published
March 2019
Language
English (United States)
Last Update
2019-05-24
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A table-specific disk I/O integrity checksum level. The checksum setting applies to primary data rows, fallback data rows, and all secondary index rows for the join index.

ON
Calculate checksums using the entire disk block. Sample 100% of the disk blocks to generate a checksum. ON is equivalent to ALL, which is deprecated.
OFF
Disables checksum disk I/O integrity checks. OFF is equivalent to NONE, which is deprecated.
DEFAULT
The default setting is the current DBS Control checksum setting specified for this table type.

Example: Specifying a Disk I/O Integrity Checksum for a Join Index

The following example defines a join index with a disk I/O integrity checksum specification of ON. If secondary indexes are defined on ord_cust_idx , then the specified checksum value also applies to them.

    CREATE JOIN INDEX ord_cust_idx, CHECKSUM=ON AS
    SELECT c_nationkey, SUM(o_totalprice(FLOAT)) AS price, o_orderdate 
    FROM orders, customer 
    WHERE o_custkey = c_custkey 
    GROUP BY c_nationkey, o_orderdate
    ORDER BY o_orderdate;