Data & code

.DB-SHM

Analyser by valjdakosta

SQLite shared-memory index (.db sidecar)

Version
0.00
Status
Local-only
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Home › Formats › .DB-SHMID

What is a .DB-SHM file?

A .db-shm file is the shared-memory WAL index for a SQLite database stored as .db, coordinating concurrent access to its write-ahead log. Same format as .sqlite-shm.

Did you know
  • Both WAL sidecars (-wal and -shm) exist only while a database uses WAL journalling mode, and disappear on a clean shutdown.
  • The -shm file tracks which logged pages each reader should see, so several programs can read a busy .db at once without locking each other out.
  • It holds no database rows - only bookkeeping about the -wal log - so it never needs to be backed up.
  • If the matching -wal is gone the -shm is meaningless, and SQLite simply discards it.
What Analyser reads
Open SQLite databases (.sqlite/.db/.sqlite3) and read their full schema in-browser - every table with its columns and row counts, views, indexes, triggers, the CREATE-statement DDL, and a sample of the largest table. Reads the WAL-mode sidecars too: the Write-Ahead Log (-wal) - page size, salts, frame and committed-transaction counts, and the pages it changed - and the shared-memory index (-shm) - valid frame count, database size and checkpoint progress. Also parses .sql dumps (dialect, tables, columns, INSERT counts) and identifies Microsoft Access (MDB, ACCDB).
Depth of analysis
.DB-SHM is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
Open a .DB-SHM file
Drag a .DB-SHM file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.