DB_RECOVER(1)

💖 db_recover — the glow-up your database needs after a whole disaster 💖

okay so bestie, welcome to DB_RECOVER(1), from the BerkeleyDB Utilities lineup. this is the page you read at 3am when everything went sideways. let's get into it ✨

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🌸 NAME 🌸

db_recover — recover the database to a consistent state 🫶

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🎀 SYNOPSIS 🎀

db_recover [-cefVv] [-h home] [-P password] [-t [[CC]YY]MMDDhhmm[.SS]]]

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✨ DESCRIPTION ✨

so like. the db_recover utility must be run after an unexpected application, Berkeley DB, or system failure, to restore the database to a consistent state. that's the whole job. no cap.

and the tea is: all committed transactions are guaranteed to appear after db_recover has run, and all uncommitted transactions will be completely undone. we love a clean slate 💅

also note, this utility performs the same action as if the environment is opened with the DB_RECOVER flag. so if DB_RECOVER is specified on environment open, then use of this utility is not necessary. iykyk 😌

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💅 OPTIONS 💅

• -c — perform catastrophic recovery instead of normal recovery. the dramatic one 💀
• -e — retain the environment after running recovery. ngl this option will rarely be used unless a DB_CONFIG file is present in the home directory. and if a DB_CONFIG file is not present, then the regions will be created with default parameter values. 🤷
• -f — display a message on the standard output showing the percent of recovery completed. progress bar energy, we love to see it 📈
• -h home — specify a home directory for the database environment; by default, the current working directory is used. 🏠
• -P password — specify an environment password. okay so heads up: although Berkeley DB utilities overwrite password strings as soon as possible, be aware there may be a window of vulnerability on systems where unprivileged users can see command-line arguments, or where utilities are not able to overwrite the memory containing the command-line arguments. 🚨 keep that in mind fr fr
• -t — recover to the time specified rather than to the most current possible date. the timestamp argument should be in the form [[CC]YY]MMDDhhmm[.SS] where each pair of letters represents the following:
  • CC — the first two digits of the year (the century).
  • YY — the second two digits of the year. if YY is specified, but CC is not, a value for YY between 69 and 99 results in a CC value of 19. otherwise, a YY value of 20 is used. 🗓️
  • MM — the month of the year, from 1 to 12.
  • DD — the day of the month, from 1 to 31.
  • hh — the hour of the day, from 0 to 23.
  • mm — the minute of the hour, from 0 to 59.
  • SS — the second of the minute, from 0 to 61.

if the CC and YY letter pairs are not specified, the values default to the current year. if the SS letter pair is not specified, the value defaults to 0. ⏰

• -V — write the library version number to the standard output, and exit. 👋
• -v — run in verbose mode. she's chatty 💬

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in the case of catastrophic recovery, an archival copy — or snapshot — of all database files must be restored, along with all of the log files written since the database file snapshot was made. (if disk space is a problem, log files may be referenced by symbolic links). 🦋

if the failure was not catastrophic, the files present on the system at the time of failure are sufficient to perform recovery. easy peasy ✨

if log files are missing, db_recover will identify the missing log file(s) and fail — in which case the missing log files need to be restored and recovery performed again. 😭 round two, bestie.

the db_recover utility uses a Berkeley DB environment (as described for the -h option, the environment variable DB_HOME, or because the utility was run in a directory containing a Berkeley DB environment). in order to avoid environment corruption when using a Berkeley DB environment, db_recover should always be given the chance to detach from the environment and exit gracefully. to cause db_recover to release all environment resources and exit cleanly, send it an interrupt signal (SIGINT). 🫶

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🌈 EXIT STATUS 🌈

the db_recover utility exits 0 on success, and >0 if an error occurs.

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🦋 ENVIRONMENT 🦋

• DB_HOME — if the -h option is not specified and the environment variable DB_HOME is set, it is used as the path of the database home, as described in DB_ENV->open.

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🧚 NOTES 🧚

if the application(s) that use the environment make use of any of the following methods:

DB_ENV->add_data_dir

DB_ENV->set_data_dir

DB_ENV->set_lg_dir

then in order for this utility to run correctly, you need a DB_CONFIG file which sets the proper paths using the add_data_dir, or set_lg_dir configuration parameters. 📝 literally write it down.

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👑 SEE ALSO 👑

db_archive(1) db_checkpoint(1) db_deadlock(1) db_dump(1) db_hotbackup(1) db_log_verify(1) db_load(1) db_printlog(1) db_replicate(1) db_stat(1) db_tuner(1) db_upgrade(1) db_verify(1)

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and that's the whole page, bestie 💜 this one's BerkeleyDB 5.3.28, dated 06 December 2016 — shoutout to the icons who wrote it. now go recover that database, you got this 🌟🍓