Indodb21 May 2026

If the OS crashes while writing a 16KB page, only part of it may be written. InnoDB writes the page to a doublewrite buffer first, then to the real location. On recovery, it detects corruption and restores from the doublewrite copy.

InnoDB supports standard SQL isolation levels. The default is REPEATABLE READ, which uses MVCC + gap locks to prevent phantom reads. indodb21

| Isolation Level | Dirty Read | Non-repeatable Read | Phantom Read | Concurrency | |----------------|------------|---------------------|--------------|--------------| | READ UNCOMMITTED | Yes | Yes | Yes | Highest | | READ COMMITTED | No | Yes | Yes | High | | REPEATABLE READ (default) | No | No | No (with gap locks) | Good | | SERIALIZABLE | No | No | No | Lowest | If the OS crashes while writing a 16KB

Tip for high-throughput apps: READ COMMITTED reduces gap locking and is often safer for conflict-prone workloads. InnoDB supports standard SQL isolation levels

[1] Zhong et al., PubLayNet, 2019.
[2] Li et al., DocBank, 2020.
[3] Bhunia et al., “Indic Handwritten Text Datasets,” 2019.
[4] … (add real Indic OCR papers like “BanglaLekha”, “IIIT‑H IndicOCR”, etc.)