Edited, memorised or added to reading list

on 09-Nov-2020 (Mon)

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Flashcard 6028987337996

Question
enfermedad
Answer
disease/sickness

statusnot learnedmeasured difficulty37% [default]last interval [days]               
repetition number in this series0memorised on               scheduled repetition               
scheduled repetition interval               last repetition or drill






When comitting, SQLite upgrades RESERVED lock to a PENDING lock when the transaction looks to commit.
statusnot read reprioritisations
last reprioritisation on reading queue position [%]
started reading on finished reading on

Unknown title
ransaction can hold this lock at a time, others wanting to write fail with SQLITE_BUSY. A transaction may upgrade it’s SHARED lock to a RESERVED lock to write after a read, but not vice versa. W<span>hen comitting, SQLite upgrades RESERVED lock to a PENDING lock when the transaction looks to commit. PENDING lock waits for readers to finish reading and blocks new readers from acquiring SHARED with SQLITE_BUSY. PENDING lock is upgraded to EXCLUSIVE lock after all SHARED locks are rel




#has-images #sqlite
Rollback journal and 2PL

In this mode, locks are used to implement isolation. The locks acquired are coarse-grained and apply to the entire database. The locks permit a single writer and simultaneous readers from concurrent transactions to co-exist. Writers holding a RESERVED lock block writers from other concurrent transactions. Writers holding a PENDING lock block readers and writers from other concurrent transactions.

statusnot read reprioritisations
last reprioritisation on reading queue position [%]
started reading on finished reading on

Unknown title
or power failure, the database can get back to its previous state. We’ll look at the two5 journaling modes SQLite supports, Rollback journal and WAL. Both modes implement isolation differently. <span>Rollback journal and 2PL In this mode, locks are used to implement isolation. The locks acquired are coarse-grained and apply to the entire database. The locks permit a single writer and simultaneous readers from concurrent transactions to co-exist. Writers holding a RESERVED lock block writers from other concurrent transactions. Writers holding a PENDING lock block readers and writers from other concurrent transactions. Algorithm description Transaction wanting to read acquires a SHARED lock. Multiple transactions can hold this lock simultaneously. Transaction wanting to write acquires a RESERVED lock.