Glossary for database administrators
This page is for database administrators who meet an Exponential term they do not know. Each entry is one or two sentences with a link to the page that explains it.
Contents
A to D
Adapter (MongoDB): expMongoDB, the driver that translates the kernel's SQL-shaped calls into MongoDB operations;
it never runs SQL (MongoDB: limits).
Alias (driver alias): the value of DatabaseImplementation, such as sqlite3 or ezmysqli, mapped to a driver
class by ImplementationAlias[] (DatabaseSettings reference).
Audit tables: expaudit_cursor, expaudit_event, expaudit_file, the index of the audit trail, created by the
6.0.15 update or createaudittables.php (6.0.15 update).
Cluster (DFS): several web servers sharing files on an NFS mount, with metadata in the table ezdfsfile
(Clustering).
Cronjob part: a named list of scripts in cronjob.ini, run by runcronjobs.php <part>
(Housekeeping).
.dba: Exponential's engine-neutral schema and data format, a PHP array (The .dba format).
DatabaseSettings: the block of site.ini with the connection (Reference).
Delayed indexing: publishing queues search indexing in ezpending_actions for a cronjob
(Search index tables).
DRCP: Oracle's Database Resident Connection Pooling, offered by ezoracle (Oracle tuning).
Driver: the class that talks to one engine, implementing eZDBInterface (The database layer).
E to M
eZDB: the kernel's entry point to the database, eZDB::instance(); the name is a kernel identifier.
ezoracle: the extension that provides Oracle support, required by composer.json (Setting up Oracle).
ezsite_data: the table holding the database's version rows ezpublish-version and ezpublish-release; the names
keep their historic spelling (Upgrades).
Kickstarter: an installer driven by kickstart.ini; its database type is [database_choice] Type=.
Maintenance mode: visitors get a 503 page while you work; php bin/php/maintenance.php on|off|status
(Maintenance mode).
MONGO TODO: the log marker of SQL the MongoDB adapter could not translate.
N to S
Null database (eZNullDB): what eZDB::instance() returns when the alias names no driver; every page then fails.
Override: a settings file in settings/override/ (or a siteaccess) that changes a shipped value without editing
it (Reading and changing settings).
pgcrypto: the PostgreSQL extension whose digest() the driver uses for MD5 (Setting up PostgreSQL).
Query cache: the optional cache of SELECT results, querycache.ini (The SQL query cache).
Schema handler: the class that turns .dba into an engine's DDL and back, registered in dbschema.ini.
Siteaccess: one way into an installation (a site, the administration) with its own settings, possibly its own database.
Slave server: Exponential's setting name for a MySQL or MariaDB read replica (UseSlaveServer)
(Read replicas).
T to Z
Update file: an SQL file in update/database/<engine>/<version>/ that takes a database from one version to the
next (Upgrades).
Upgrade check: Setup > Upgrade check, which compares files and the database schema with the release (Checking the schema).
Velocity: Exponential's own application server with persistent workers; each worker keeps its connection, so it must be restarted after a database settings change.
WAL: SQLite's write-ahead log, the -wal file; readers and the writer work side by side
(SQLite for DBAs).
Writer lock: the .writer-lock file with which the SQLite driver queues writers
(Write queue).
Related pages
- Glossary for hosts
- Database FAQ
- Database administrators: start here
- Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.
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