17.05 - File System: Segments Released Columns - Teradata Database

Teradata Vantageā„¢ - 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 identify the total disk memory segments released by the File System, as well as those segments that are dropped from memory during the log period. When a segment is released, the segment is either:
  • Force out of memory (F)
  • Remains resident in memory (R)
  • Aged out of memory (A), from segments that remain resident

Both the number of segments (Rels, Writes, Drps) and the size of the segments (RelKB, WriteKB, DrpKB) are counted. When a segment leaves memory, it must be written to disk only if the segment is dirty, that is, modified (Dy). Otherwise, the clean or unmodified (Cn) segment is simply dropped.

Most spool blocks are simply dropped from a task and put on the age queue. This may happen multiple times. Each of these will be counted as a resident release. If the system is low on memory and the age queue must be processed, this may also result in an age write or age drop. Forced writes are always also counted as either clean resident releases or forced drops, depending on whether age normal or age out now was specified.

Column Name Mode Description Data Type
FileAPtDyRRels count Number of dirty append table and permanent journal data block or cylinder index disk segment resident releases. FLOAT
FilePCiDyRRels count Number of dirty permanent cylinder index disk segment resident releases. FLOAT
FilePDbDyRRels count Number of dirty permanent data block disk segment resident releases. FLOAT
FileSCiDyRRels count Number of dirty regular or restartable spool cylinder index disk segment resident releases. FLOAT
FileSDbDyRRels count Number of dirty regular or restartable spool data block disk segment resident releases. FLOAT
FileTJtDyRRels count Number of dirty transient journal table or WAL data block or WAL cylinder index disk segment resident releases. FLOAT
FileAPtDyRRelKB count KB released by FileAPtDyRRels. FLOAT
FilePCiDyRRelKB count KB released by FilePCiDyRRels. FLOAT
FilePDbDyRRelKB count KB released by FilePDbDyRRels. FLOAT
FileSCiDyRRelKB count KB released by FileSCiDyRRels. FLOAT
FileSDbDyRRelKB count KB released by FileSDbDyRRels. FLOAT
FileTJtDyRRelKB count KB released by FileTJtDyRRels. FLOAT
FileAPtFWrites count Number of append table and permanent journal data block or cylinder index disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FilePCiFWrites count Number of permanent cylinder index disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FilePDbFWrites count Number of permanent data block disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FileSCiFWrites count Number of regular or restartable spool cylinder index disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FileSDbFWrites count Number of regular or restartable spool data block disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FileTJtFWrites count Number of transient journal table or WAL data block or WAL cylinder index disk segment forced releases or specific I/O requests causing an immediate physical write. FLOAT
FileAPtFWriteKB count KB written by FileAPtFWrites. FLOAT
FilePCiFWriteKB count KB written by FilePCiFWrites. FLOAT
FilePDbFWriteKB count KB written by FilePDbFWrites. FLOAT
FileSCiFWriteKB count KB written by FileSCiFWrites. FLOAT
FileSDbFWriteKB count KB written by FileSDbFWrites. FLOAT
FileTJtFWriteKB count KB written by FileTJtFWrites. FLOAT