LiveCache 101

1. Livecache users :
    a. control (db level, DBM user/operator) – admin
    b. superdba (db level, SYSDBA user) – used in sqlstudio
    c. sap<lcsid> (db level, schema livecache owner)
    d. sdb (os level, group sdba)
    e. lcdadm ( os level, group sdba)

2. LVC contains OMS for LCA routines. Stored in memory i.e data cache. During checkpoint/stop, cache written to disk. LCA routines is store procedures. No I/O

3. ONLY LC10 MUST be used to stop and start Livecache

4. Log files :
    a. knldiag, knldiag.old and knldiag.err (system msg)
    b. lcinit.log (start/stop)

5. Directory structure consists of database independent and dependent
    – Dependent path – /sapdb/SID/db
    – Independent data path – /sapdb/SID/ (dbmcli dbm_getpath IndepDataPath)
    – Independent program path – /sapdb/program (dbmcli dbm_getpath IndepProgPath)
    – Run directory -  /sapdb/data/wrk/SID
   – Data/log volume – /sapdb/LCD/data or log

6. Three connections LCA for APO, LDA for ATP & LEA

7. Memory Areas:
   a. CACHE_SIZE – persistent allocated when startup. Swap to data file if cache size is too small
   b. OMS_HEAP_LIMIT – local memory

Heap usage monitoring /SAPAPO/OM_LC_MEM_MEMORY.

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~ by onnry on July 5, 2008.