Hi, Encountered what seemed to be somewhat excessive memory consumption for a relatively simple statement prepare. The following was carried out in sequence. Platform/environment is Windows CE.
1. System and SQLite memory statistics obtained and recorded 2. Preparation of SQLite statement. The query is : "select docid, upper(words) from Homonyms;" on table of schema : 'CREATE VIRTUAL TABLE Homonyms using fts4(words , tokenize=simpleplus "&/"); ' (simpleplus refers to a custom FTS tokenizer.) There are about 80 records/rows in the table. 3. Statement is finalized. 4. System and SQLite memory statistics obtained and recorded again for comparison So comparing memory statistics changes at 4 over 1, the following was noted (figures are in bytes) -> dwAvailPhys (system physical memory) decrease by : 1,286,144 -> dwAvailVirtual (system virtual memory) decrease by : 1,376,256 -> SQLITE_STATUS_PAGECACHE_OVERFLOW status increase by : 304,704 (I understand it here to be page cache use, please correct/enlighten me if I'm mistaken) -> SQLITE_STATUS_MEMORY_USED increase by : 801,440 (other general memory use by SQLite) -> SQLITE_DBSTATUS_CACHE_USED increase by : 304,704 (memory use for page cache by database, perhaps understandably identical to the overflow figure above) -> SQLITE_DBSTATUS_SCHEMA_USED increase by : 495,224 (memory used to store database schema - why the sudden increase at this point?) It was a little strange that such memory consumption could not be observed when a similar query/statement prepare was carried out on other tables. It is of concern as we are trying to find ways to reduce or eliminate precious run-time memory usage by the application where we can. The following numbers may be superfluous, but hope it will help in better shedding light on the behaviour. The sections are as reported by the GlobalMemoryStatus(), sqlite3_status() and sqlite_db_status() functions respectively. Many thanks - Herfian Memory statistics before statement prepare (at 1): dwLength : 32 dwMemoryLoad : 35 dwTotalPhys : 112959488 dwAvailPhys : 73674752 dwTotalPageFile : 0 dwAvailPageFile : 0 dwTotalVirtual : 1073741824 dwAvailVirtual : 824377344 SQLITE_STATUS_MEMORY_USED : 1299608 SQLITE_STATUS_MALLOC_SIZE : 48000 SQLITE_STATUS_MALLOC_COUNT : 13785 SQLITE_STATUS_PAGECACHE_USED : 0 SQLITE_STATUS_PAGECACHE_OVERFL : 342792 SQLITE_STATUS_PAGECACHE_SIZE : 4232 SQLITE_STATUS_SCRATCH_USED : 0 SQLITE_STATUS_SCRATCH_OVERFLOW : 0 SQLITE_STATUS_SCRATCH_SIZE : 0 SQLITE_DBSTATUS_LOOKASIDE_USED : 8 SQLITE_DBSTATUS_LOOKASIDE_HIT : 0 SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE : 0 SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL : 0 SQLITE_DBSTATUS_CACHE_USED : 4808 SQLITE_DBSTATUS_SCHEMA_USED : 0 SQLITE_DBSTATUS_STMT_USED : 0 Memory statistics after statement finalize (at 4): dwLength : 32 dwMemoryLoad : 36 dwTotalPhys : 112959488 dwAvailPhys : 72388608 dwTotalPageFile : 0 dwAvailPageFile : 0 dwTotalVirtual : 1073741824 dwAvailVirtual : 823001088 SQLITE_STATUS_MEMORY_USED : 2101048 SQLITE_STATUS_MALLOC_SIZE : 48000 SQLITE_STATUS_MALLOC_COUNT : 26878 SQLITE_STATUS_PAGECACHE_USED : 0 SQLITE_STATUS_PAGECACHE_OVERFL : 647496 SQLITE_STATUS_PAGECACHE_SIZE : 4232 SQLITE_STATUS_SCRATCH_USED : 0 SQLITE_STATUS_SCRATCH_OVERFLOW : 0 SQLITE_STATUS_SCRATCH_SIZE : 0 SQLITE_DBSTATUS_LOOKASIDE_USED : 9 SQLITE_DBSTATUS_LOOKASIDE_HIT : 0 SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE : 1447 SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL : 0 SQLITE_DBSTATUS_CACHE_USED : 309512 SQLITE_DBSTATUS_SCHEMA_USED : 495224 SQLITE_DBSTATUS_STMT_USED : 0 _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
