Disk Store File Names and Extensions

Disk store files include store management and access control files and the operation log, or oplog, files, consisting of one file for deletions and another for all other operations.

The next table describe file names and extensions; they are followed by example disk store files.

File Names

File names have three parts.

First Part of File Name: Usage Identifier

Usage Identifier Values Usage Examples
OVERFLOW Oplog data from overflow tables and queues only. OVERFLOWoverflowDS1_1.crf
BACKUP Oplog data from persistent and persistent+overflow tables and queues. BACKUPoverflowDS1.if, BACKUPGFXD-DEFAULT-DISKSTORE.if
DRLK_IF Access control - locking the disk store. DRLK_IFoverflowDS1.lk, DRLK_IFGFXD-DEFAULT-DISKSTORE.lk

Second Part of File Name: Disk Store Name

Disk Store Name Values Usage Examples
<disk store name> Non-default disk stores. name="OVERFLOWDS1" DRLK_IFOVERFLOWDS1.lk, name="PERSISTDS1" BACKUPPERSISTDS1_1.crf
Note: GemFire XD internally converts and uses disk store names in upper case characters, even if you specify lower case characters in the DDL statement.
GFXD-DEFAULT-DISKSTORE Default disk store name, used when persistence or overflow are specified on a table or queue but no disk store is named. DRLK_IFGFXD-DEFAULT-DISKSTORE.lk, BACKUPGFXD-DEFAULT-DISKSTORE_1.crf
GFXD-DD-DISKSTORE Default disk store for persisting the data dictionary. BACKUPGFXD-DD-DISKSTORE_1.crf

Third Part of File Name: oplog Sequence Number

oplog Sequence Number Usage Examples
Sequence number in the format _n Oplog data files only. Numbering starts with 1. OVERFLOWoverflowDS1_1.crf, BACKUPpersistDS1_2.crf, BACKUPpersistDS1_3.crf

File Extensions

File Extension Values Usage Notes
if Disk store metadata Stored in the first disk-dir listed for the store. Negligible size - not considered in size control.
lk Disk store access control Stored in the first disk-dir listed for the store. Negligible size - not considered in size control.
crf Oplog: create, update, and invalidate operations Pre-allocated 90% of the total max-oplog-size at creation.
drf Oplog: delete operations Pre-allocated 10% of the total max-oplog-size at creation.
krf Oplog: live key and crf offset information Created after the oplog has reached the max-oplog-size, before rolling over to a new file. Used to improve performance at startup.
irf Oplog: index recovery file Like the krf file, this file is created after the oplog has reached the max-oplog-size, before rolling over to a new file. This file contains the indexed column values that correspond to all of the live keys in the krf file. Used to improve the performance of index recovery at startup.