17.05 - File System: Depot Columns - Teradata Database

Teradata Vantage™ - Resource Usage Macros and Tables

prodname
Advanced SQL Engine
Teradata Database
vrm_release
17.00
17.05
created_date
June 2020
category
Administration
User Guide
featnum
B035-1099-170K

These columns summarize the physical writes to the Depot used to protect in-place modifications.

Column Name Mode Description Data Type
FileLargeDepotBlocks count Total number of blocks (either WAL or database) that have been protected by large depot writes.

Since a large depot write protects multiple blocks, the following calculation results in the average number of blocks protected by each large depot write:

FileLargeDepotBlocks / FileLargeDepotWrites

FLOAT
FileSmallDepotBusy count Number of times a small depot I/O request waited for a free slot.

A large number in this field indicates more small depot slots are needed. You can use the DBS Control field, SmallDepotCylsPerPdisk, to determine the number of depot cylinders the file system allocates per pdisk (storage device) to contain small slots. For more information about this DBS Control field, see Teradata Vantage™ - Database Utilities , B035-1102 .

FLOAT
FileLargeDepotBusy count Number of times a large depot I/O request waited for a free slot.

A large number in this field indicates more large depot slots are needed. You can use the DBS Control field, LargeDepotCylsPerPdisk, to determine the number of depot cylinders the file system allocates per pdisk (storage device) to contain large slots. For more information about this DBS Control field, see Teradata Vantage™ - Database Utilities , B035-1102 .

FLOAT
FileLargeDepotWrites count Number of large writes to the depot performed to protect in-place modifications. Each large depot write protects multiple in-place writes of either WAL data blocks or database data blocks. The large depot is typically used when blocks age out of memory in the background. Large depot writes are also counted against FileWrites. Therefore, FileWrites still indicates the total writes regardless of whether it was a depot write or a database write. FLOAT
FileSmallDepotWrites count Number of small writes to the depot performed to protect in-place modifications. Each small depot write protects a single in-place write of either a write ahead logging (WAL) data block or a database data block. The small depot is typically used when the in-place writes are initiated by a foreground task. Small depot writes are also counted against FileWrites. Therefore, FileWrites still indicates the total writes regardless of whether it was a depot write or a database write. FLOAT