Teradata Database Exceptions
Teradata Database in the public cloud offers the same features that come with an on-premises Teradata Database system with the following exceptions:
- Data block read-ahead count is 15 data blocks.
- Default PERM DB size for permanent tables is 254 sectors.
- Default WORK DB size for temporary tables is 254 sectors, sometimes referred to as SPOOL DB size.
- One single transaction can consume 100% of FSG cache.
- Multiple Hash Maps is not a supported feature for Teradata Database in the public cloud.
In addition, the following in-memory optimization enhancements are not supported:
- In-memory hash joins for two-step column-partitioned (CP) join, outer hash join, and partial redistribution and partial duplication (PRPD) join.
- In-memory hash joins and bulk qualification for DML statements.
- Single-instruction-multiple-data (SIMD) data-level parallel processing for:
- Predicate comparison across different data types (for example, BYTEINT and INT)
- DECIMAL data type comparisons
- Hash computation in dynamic hash joins
- AllRowsOneAMP in-memory hash join, where the in-memory optimized spool is duplicated to just one AMP.
- MVC-aware bulk qualification to more comparison operators, and MVC with run length (RL) compression and RL-aware bulk qualification.