Tales From A Lazy Fat DBA

Ever noticed while exploring ‘dbs’  folder under ORACLE_HOME location about a file name starting from ‘lk’ or ‘kl’ followed by SID in uppercase e.g lkORCL. Let me paste what are my DB’s dbs contents.

[oracle@localhost dbs]$ ls
hc_orcl.dat  init.ora  initorcl.ora  lkORCL  orapworcl  peshm_orcl_0  snapcf_orcl.f  spfileorcl.ora

These are some default files which always created under dbs, everytime your Database restarts and it if you ever tries opening this file it reads “DO NOT DELETE THIS FILE!”. lk<sid> file is used to lock shared memory for specific database but there is still no harm in deleting this file, database will keep on working normal even after deletion and will create it by it’s own after DB bounce.

for example, in our case
-rw-rw—- 1 oracle oinstall 24 Oct 9 18:04 lkORCL

(oracle owns the file and has 660 level permission)
lkORCL is used to lock shared memory for ORCL database in RAM.