MARIADB-BINLOG(1)

📦
version 13.0.2 · 22 versions
, in alpine 3.24, arch rolling, ubuntu stonking

💅 MARIADB-BINLOG(1) — the manual, but make it make sense 💅

okay so this is mariadb-binlog(1) from MariaDB Database System, and it's giving “utility for processing binary log files” energy. Also the NAME section literally says mariadb-binlog is now a symlink to mariadb-binlog — yes, bestie, that's what it says, and I'm not editing facts 💀.

✨ NAME ✨

mariadb-binlog — utility for processing binary log files (mariadb-binlog is now a symlink to mariadb-binlog).

🦋 SYNOPSIS 🦋

mariadb-binlog [options] log_file ...

🌸 DESCRIPTION 🌸

The server's binary log consists of files containing “events” that describe modifications to database contents. The server writes these files in binary format. To display their contents in text format, use the mariadb-binlog utility. You can also use mariadb-binlog to display the contents of relay log files written by a slave server in a replication setup because relay logs have the same format as binary logs.

Invoke mariadb-binlog like this:

shell> mariadb-binlog [options] log_file ...

For example, to display the contents of the binary log file named binlog.000003, use this command:

shell> mariadb-binlog binlog.0000003

The output includes events contained in binlog.000003. For statement-based logging, event information includes the SQL statement, the ID of the server on which it was executed, the timestamp when the statement was executed, how much time it took, and so forth. For row-based logging, the event indicates a row change rather than an SQL statement.

Events are preceded by header comments that provide additional information. For example:

# at 141
#100309  9:28:36 server id 123  end_log_pos 245
  Query thread_id=3350  exec_time=11  error_code=0

In the first line, the number following at indicates the starting position of the event in the binary log file.

The second line starts with a date and time indicating when the statement started on the server where the event originated. For replication, this timestamp is propagated to slave servers. server id is the server_id value of the server where the event originated. end_log_pos indicates where the next event starts (that is, it is the end position of the current event + 1). thread_id indicates which thread executed the event. exec_time is the time spent executing the event, on a master server. On a slave, it is the difference of the end execution time on the slave minus the beginning execution time on the master. The difference serves as an indicator of how much replication lags behind the master. error_code indicates the result from executing the event. Zero means that no error occurred.

The output from mariadb-binlog can be re-executed (for example, by using it as input to mariadb) to redo the statements in the log. This is useful for recovery operations after a server crash. For other usage examples, see the discussion later in this section.

Normally, you use mariadb-binlog to read binary log files directly and apply them to the local MariaDB server. It is also possible to read binary logs from a remote server by using the --read-from-remote-server option. To read remote binary logs, the connection parameter options can be given to indicate how to connect to the server. These options are --host, --password, --port, --protocol, --socket, and --user; they are ignored except when you also use the --read-from-remote-server option.

mariadb-binlog supports the following options, which can be specified on the command line or in the [mariadb-binlog] and [client] option file groups. Yes, all of them. Buckle up.

  • --help, -? — display a help message and exit.
  • --base64-output=value — this option determines when events should be displayed encoded as base-64 strings using BINLOG statements. The option has these allowable values (not case sensitive):
    • AUTO (“automatic”) or UNSPEC (“unspecified”) — displays BINLOG statements automatically when necessary (that is, for format description events and row events). This is the default if no --base64-output option is given.
Note — automatic BINLOG display is the only safe behavior if you intend to use the output of mariadb-binlog to re-execute binary log file contents. The other option values are intended only for debugging or testing purposes because they may produce output that does not include all events in executable form.
  • NEVER — causes BINLOG statements not to be displayed. mariadb-binlog exits with an error if a row event is found that must be displayed using BINLOG.
  • DECODE-ROWS — specifies to mariadb-binlog that you intend for row events to be decoded and displayed as commented SQL statements by also specifying the --verbose option. Like NEVER, DECODE-ROWS suppresses display of BINLOG statements, but unlike NEVER, it does not exit with an error if a row event is found.

The --base64-output can be given as --base64-output or --skip-base64-output (with the sense of AUTO or NEVER).

For examples that show the effect of --base64-output and --verbose on row event output, see the section called “MARIADB-BINLOG ROW EVENT DISPLAY”.

  • --binlog-row-event-max-size=path — the directory where character sets are installed. (yes, that's the description the page gives here too — not me, I'm just reporting the facts 💀)
  • --character-sets-dir=path — the directory where character sets are installed.
  • --database=db_name, -d db_name — this option causes mariadb-binlog to output entries from the binary log (local log only) that occur while db_name has been selected as the default database by USE.

The --database option for mariadb-binlog is similar to the --binlog-do-db option for mariadbd, but can be used to specify only one database. If --database is given multiple times, only the last instance is used.

The effects of this option depend on whether the statement-based or row-based logging format is in use, in the same way that the effects of --binlog-do-db depend on whether statement-based or row-based logging is in use.

Statement-based logging. The --database option works as follows:

  • While db_name is the default database, statements are output whether they modify tables in db_name or a different database.
  • Unless db_name is selected as the default database, statements are not output, even if they modify tables in db_name.
  • There is an exception for CREATE DATABASE, ALTER DATABASE, and DROP DATABASE. The database being created, altered, or dropped is considered to be the default database when determining whether to output the statement.

Suppose that the binary log was created by executing these statements using statement-based-logging:

INSERT INTO test.t1 (i) VALUES(100);
INSERT INTO db2.t2 (j)  VALUES(200);
USE test;
INSERT INTO test.t1 (i) VALUES(101);
INSERT INTO t1 (i)      VALUES(102);
INSERT INTO db2.t2 (j)  VALUES(201);
USE db2;
INSERT INTO test.t1 (i) VALUES(103);
INSERT INTO db2.t2 (j)  VALUES(202);
INSERT INTO t2 (j)      VALUES(203);

mariadb-binlog --database=test does not output the first two INSERT statements because there is no default database. It outputs the three INSERT statements following USE test, but not the three INSERT statements following USE db2.

mariadb-binlog --database=db2 does not output the first two INSERT statements because there is no default database. It does not output the three INSERT statements following USE test, but does output the three INSERT statements following USE db2.

Row-based logging. mariadb-binlog outputs only entries that change tables belonging to db_name. The default database has no effect on this. Suppose that the binary log just described was created using row-based logging rather than statement-based logging. mariadb-binlog --database=test outputs only those entries that modify t1 in the test database, regardless of whether USE was issued or what the default database is. If a server is running with binlog_format set to MIXED and you want it to be possible to use mariadb-binlog with the --database option, you must ensure that tables that are modified are in the database selected by USE. (In particular, no cross-database updates should be used.)

Note — this option did not work correctly for mariadb-binlog with row-based logging prior to MySQL 5.1.37.
  • --debug[=debug_options], -# [debug_options] — write a debugging log. A typical debug_options string is 'd:t:o,file_name'. The default is 'd:t:o,/tmp/mariadb-binlog.trace'.
  • --debug-check — print some debugging information when the program exits.
  • --debug-info — print debugging information and memory and CPU usage statistics when the program exits.
  • --defaults-extra-file=name — read this file after the global files are read.
  • --defaults-file=name — only read default options from the given file.
  • --default-auth=name — default authentication client-side plugin to use.
  • --disable-log-bin, -D — disable binary logging. This is useful for avoiding an endless loop if you use the --to-last-log option and are sending the output to the same MariaDB server. This option also is useful when restoring after a crash to avoid duplication of the statements you have logged.

This option requires that you have the SUPER privilege. It causes mariadb-binlog to include a SET sql_log_bin = 0 statement in its output to disable binary logging of the remaining output. The SET statement is ineffective unless you have the SUPER privilege.

  • --flashback, -B — support flashback mode.
  • --force-if-open — force if binlog was not closed properly. Defaults to on; use --skip-force-if-open to disable.
  • --force-read, -f — with this option, if mariadb-binlog reads a binary log event that it does not recognize, it prints a warning, ignores the event, and continues. Without this option, mariadb-binlog stops if it reads such an event.
  • --hexdump, -H — display a hex dump of the log in comments, as described in the section called “MARIADB-BINLOG HEX DUMP FORMAT”. The hex output can be helpful for replication debugging.
  • --host=host_name, -h host_name — get the binary log from the MariaDB server on the given host.
  • --local-load=path, -l path — prepare local temporary files for LOAD DATA INFILE in the specified directory.
  • --no-defaults
  • Don't read default options from any option file. (yes, this is the tail end of that one — you know the vibe 💅)
  • --offset=N, -o N — skips the first N entries in the log. like, scroll past the first N slides bestie, we're not looking at those 🌸
  • --open-files-limit=NUM — sets the open_files_limit variable, which reserves file descriptors for mariadb-binlog. give the girl some room to breathe 🫶
  • --password[=password], -p[password] — the password for connecting to the server. If you use the short form (-p), you cannot have a space between the option and the password. If you leave the password value off after --password or -p on the command line, mariadb-binlog will prompt you for one.
Specifying a password on the command line should be considered insecure. You can use an option file to avoid giving the password on the command line. seriously, protect your secrets 🙈
  • --plugin-dir=dir_name — directory for client-side plugins. that's where the plugin besties live 🎀
  • --print-defaults — print the program argument list from all option files and exit. a little peek behind the curtain ✨
  • --port=port_num, -P port_num — the TCP/IP port number for connecting to a remote server, or 0 for default to, in order of preference, my.cnf, $MYSQL_TCP_PORT, /etc/services, built-in default (3306). Forces --protocol=tcp when specified on the command line without other connection properties. the way it just forces tcp, iconic 👑
  • --protocol={TCP|SOCKET|PIPE|MEMORY} — the connection protocol to use for connecting to the server. Useful when the other connection parameters would normally cause a protocol to be used other than the one you want. we pick our own lane 💅
  • --raw — requires -R. Output raw binlog data instead of SQL statements. Output files named after server logs. no translation, just vibes 🔥
  • --read-from-remote-server, -R — read the binary log from a MariaDB server rather than reading a local log file. Any connection parameter options are ignored unless this option is given as well. These options are --host, --password, --port, --protocol, --socket, and --user.

This option requires that the remote server be running. It works only for binary log files on the remote server, not relay log files. (relay logs said "not today" 💀)

  • --result-file=name, -r name — direct output to the given file. With --raw this is a prefix for the file names.
  • --rewrite-db=name, -r name — updates to a database with a different name than the original. Example: rewrite-db='from->to'. For events that are binlogged as statements, rewriting the database constitutes changing a statement's default database from db1 to db2. There is no statement analysis or rewrite of any kind, that is, if one specifies "db1.tbl" in the statement explicitly, that occurrence won't be changed to "db2.tbl". Row-based events are rewritten correctly to use the new database name. Filtering (e.g. with --database=name) happens after the database rewrites have been performed. If you use this option on the command line and > has a special meaning to your command interpreter, quote the value (e.g. --rewrite-db="oldname->newname").
heads up: the > thing will absolutely get eaten by your shell if you don't quote it. protect the arrow 🏹
  • --server-id=id — display only those events created by the server having the given server ID. only that server's lore, nobody else's 🦋
  • --set-charset=charset_name — add a SET NAMES charset_name statement to the output to specify the character set to be used for processing log files.
  • --short-form, -s — display only the statements contained in the log, no extra info and no row-based events.
This is for testing only, and should not be used in production systems. If you want to suppress base64-output, consider using --base64-output=never instead. fr fr, testing only 🧚
  • --socket=path, -S path — for connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use. Forces --protocol=socket when specified on the command line without other connection properties; on Windows, forces --protocol=pipe. it just self-assigns the protocol, main character energy 💜
  • --start-datetime=datetime — start reading the binary log at the first event having a timestamp equal to or later than the datetime argument. The datetime value is relative to the local time zone on the machine where you run mariadb-binlog. The value should be in a format accepted for the DATETIME or TIMESTAMP data types. For example:
shell> mariadb-binlog --start-datetime="2014-12-25 11:25:56" binlog.000003

This option is useful for point-in-time recovery. time travel but make it SQL ⭐

  • --start-position=N, -j N — start reading the binary log at N. Type can either be a positive integer or a GTID list. When using a positive integer, the value only applies to the first binlog passed on the command line, and the first event that has a position equal to or greater than N is printed. In GTID mode, multiple GTIDs can be passed as a comma separated list, where each must have a unique domain id. The list represents the gtid binlog state that the client (another "slave" server) is aware of. Therefore, each GTID is exclusive; only events after a given sequence number will be printed to allow users to receive events after their current state.

This option is useful for point-in-time recovery.

  • --gtid-strict-mode — process binlog according to gtid-strict-mode specification. The start, stop positions are verified to satisfy start < stop comparison condition. Sequence numbers of any gtid domain must comprise monotically growing sequence. she's strict and she's right 🎀
  • --stop-datetime=datetime — stop reading the binary log at the first event having a timestamp equal to or later than the datetime argument. This option is useful for point-in-time recovery. See the description of the --start-datetime option for information about the datetime value.

This option is useful for point-in-time recovery. (yes it says it twice, and yes it means it 😭)

  • --stop-never — wait for more data from the server instead of stopping at the end of the last log. Implies --to-last-log. she does not stop, she waits 🌈
  • --stop-never-slave-server-id — the slave server_id used for --read-from-remote-server --stop-never.
  • --stop-position=N — stop reading the binary log at the first event having a position equal to or greater than N. Type can either be a positive integer or a GTID list. When using a positive integer, the value only applies to the last log file named on the command line. When in GTID mode, multiple GTIDs can be passed as a comma separated list, where each must have a unique domain id. Each GTID is inclusive; only events up to the given sequence numbers are printed.

This option is useful for point-in-time recovery.

  • --table, -T — list entries for just this table (local log only). one table, one spotlight 💖
  • --to-last-log, -t — do not stop at the end of the requested binary log from a MariaDB server, but rather continue printing until the end of the last binary log. If you send the output to the same MariaDB server, this may lead to an endless loop, so this option requires --read-from-remote-server. do not trap yourself in a loop bestie 💀
  • --user=user_name, -u user_name — the MariaDB username to use when connecting to a remote server.
  • --verbose, -v — reconstruct row events and display them as commented SQL statements. If this option is given twice, the output includes comments to indicate column data types and some metadata. If this option is given three times, the output includes diagnostic warnings about event integrity before program exit. more -v = more lore, escalating levels of detail 👑

For examples that show the effect of --base64-output and --verbose on row event output, see the section called "MARIADB-BINLOG ROW EVENT DISPLAY".

  • --version, -V — display version information and exit. drop the version and dip ✌️

You can also set the following variable by using --var_name=value syntax:

  • open_files_limit — specify the number of open file descriptors to reserve. same energy as --open-files-limit=NUM, just built different 🫶

You can pipe the output of mariadb-binlog into the mariadb client to execute the events contained in the binary log. This technique is used to recover from a crash when you have an old backup. For example:

shell> mariadb-binlog binlog.000001 | mariadb -u root -p

Or:

shell> mariadb-binlog binlog.[0-9]* | mariadb -u root -p

You can also redirect the output of mariadb-binlog to a text file instead, if you need to modify the statement log first (for example, to remove statements that you do not want to execute for some reason). After editing the file, execute the statements that it contains by using it as input to the mariadb program:

shell> mariadb-binlog binlog.000001 > tmpfile
shell> ... edit tmpfile ...
shell> mariadb -u root -p < tmpfile

When mariadb-binlog is invoked with the --start-position option, it displays only those events with an offset in the binary log greater than or equal to a given position (the given position must match the start of one event). It also has options to stop and start when it sees an event with a given date and time. This enables you to perform point-in-time recovery using the --stop-datetime option (to be able to say, for example, "roll forward my databases to how they were today at 10:30 a.m."). the way you can just say that 🌸

✨ the unsafe multi-connection thing, pls read ✨

If you have more than one binary log to execute on the MariaDB server, the safe method is to process them all using a single connection to the server. Here is an example that demonstrates what may be unsafe:

shell> mariadb-binlog binlog.000001 | mariadb -u root -p # DANGER!!
shell> mariadb-binlog binlog.000002 | mariadb -u root -p # DANGER!!
THE # DANGER!! IS NOT DECORATIVE BESTIE. Processing binary logs this way using different connections to the server causes problems if the first log file contains a CREATE TEMPORARY TABLE statement and the second log contains a statement that uses the temporary table. When the first mariadb process terminates, the server drops the temporary table. When the second mariadb process attempts to use the table, the server reports "unknown table." 😭

To avoid problems like this, use a single mariadb process to execute the contents of all binary logs that you want to process. Here is one way to do so:

shell> mariadb-binlog binlog.000001 binlog.000002 | mariadb -u root -p

Another approach is to write all the logs to a single file and then process the file:

shell> mariadb-binlog binlog.000001 >  /tmp/statements.sql
shell> mariadb-binlog binlog.000002 >> /tmp/statements.sql
shell> mariadb -u root -p -e "source /tmp/statements.sql"

mariadb-binlog can produce output that reproduces a LOAD DATA INFILE operation without the original data file. mariadb-binlog copies the data to a temporary file and writes a LOAD DATA LOCAL INFILE statement that refers to the file. The default location of the directory where these files are written is system-specific. To specify a directory explicitly, use the --local-load option. it literally rebuilds the data file from scratch, that's giving wizard behavior 🧚✨

...which is why both the client and the server you use to process those statements have to be configured with the LOCAL capability enabled. It's a whole team effort, bestie. 💅

⚠️ Warning, and I mean it: the temporary files created for LOAD DATA LOCAL statements are not automatically deleted, because they're needed until you actually execute those statements. You have to delete the temporary files yourself once you don't need the statement log anymore. Where do you find them? In the temporary file directory, and their names look like original_file_name-#-#. So go clean up after yourself, ok? 🧹

🔥 MARIADB-BINLOG HEX DUMP FORMAT 🔥

Okay so the --hexdump option makes mariadb-binlog spit out a hex dump of the binary log contents. Like this:

shell> mariadb-binlog --hexdump master-bin.000001

The hex output is made of comment lines beginning with #, so for that command above the output might look like this:

/*!40019 SET @@session.max_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
# at 4
#051024 17:24:13 server id 1  end_log_pos 98
# Position  Timestamp   Type   Master ID        Size      Master Pos    Flags
# 00000004 9d fc 5c 43   0f   01 00 00 00   5e 00 00 00   62 00 00 00   00 00
# 00000017 04 00 35 2e 30 2e 31 35  2d 64 65 62 75 67 2d 6c |..5.0.15.debug.l|
# 00000027 6f 67 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |og..............|
# 00000037 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |................|
# 00000047 00 00 00 00 9d fc 5c 43  13 38 0d 00 08 00 12 00 |.......C.8......|
# 00000057 04 04 04 04 12 00 00 4b  00 04 1a                |.......K...|
#       Start: binlog v 4, server v 5.0.15-debug-log created 051024 17:24:13
#       at startup
ROLLBACK;
Heads up 🫶 — the hex dump output currently contains the elements in the list below, but this format is subject to change. So don't go building your whole personality on it. (Want the full lore on binary log format? See http://forge.mysql.com/wiki/MySQL_Internals_Binary_Log.)
  • Position — the byte position within the log file, i.e. where you're at, literally.
  • Timestamp — the event timestamp. In the example up there, 9d fc 5c 43 is the hexadecimal representation of 051024 17:24:13. Iconic little glow-up from decimal, ngl. ✨

Type — the event type code. In the example shown, 0f means FORMAT_DESCRIPTION_EVENT ✨. The following table lists the possible type codes — here’s the full roster, bestie, no skips:

  • 00 — UNKNOWN_EVENT — this event should literally never be present in the log. If you see it, something is deeply not slaying 💀
  • 01 — START_EVENT_V3 — this indicates the start of a log file written by MySQL 4 or earlier.
  • 02 — QUERY_EVENT — the most common type of events. These contain statements executed on the master. Main character energy fr fr 👑
  • 03 — STOP_EVENT — indicates that master has stopped.
  • 04 — ROTATE_EVENT — written when the master switches to a new log file.
  • 05 — INTVAR_EVENT — used for AUTO_INCREMENT values or when the LAST_INSERT_ID() function is used in the statement.
  • 06 — LOAD_EVENT — used for LOAD DATA INFILE in MySQL 3.23.
  • 07 — SLAVE_EVENT — reserved for future use. It’s giving “placeholder era” 🎀
  • 08 — CREATE_FILE_EVENT — used for LOAD DATA INFILE statements. This indicates the start of execution of such a statement. A temporary file is created on the slave. Used in MySQL 4 only.
  • 09 — APPEND_BLOCK_EVENT — contains data for use in a LOAD DATA INFILE statement. The data is stored in the temporary file on the slave.
  • 0a — EXEC_LOAD_EVENT — used for LOAD DATA INFILE statements. The contents of the temporary file is stored in the table on the slave. Used in MySQL 4 only.
  • 0b — DELETE_FILE_EVENT — rollback of a LOAD DATA INFILE statement. The temporary file should be deleted on the slave.
  • 0c — NEW_LOAD_EVENT — used for LOAD DATA INFILE in MySQL 4 and earlier.
  • 0d — RAND_EVENT — used to send information about random values if the RAND() function is used in the statement.
  • 0e — USER_VAR_EVENT — used to replicate user variables.
  • 0f — FORMAT_DESCRIPTION_EVENT — this indicates the start of a log file written by MySQL 5 or later. Iconic little marker tbh 💅
  • 10 — XID_EVENT — event indicating commit of an XA transaction.
  • 11 — BEGIN_LOAD_QUERY_EVENT — used for LOAD DATA INFILE statements in MySQL 5 and later.
  • 12 — EXECUTE_LOAD_QUERY_EVENT — used for LOAD DATA INFILE statements in MySQL 5 and later.
  • 13 — TABLE_MAP_EVENT — information about a table definition. Used in MySQL 5.1.5 and later.
  • 14 — PRE_GA_WRITE_ROWS_EVENT — row data for a single table that should be created. Used in MySQL 5.1.5 to 5.1.17.
  • 15 — PRE_GA_UPDATE_ROWS_EVENT — row data for a single table that needs to be updated. Used in MySQL 5.1.5 to 5.1.17.
  • 16 — PRE_GA_DELETE_ROWS_EVENT — row data for a single table that should be deleted. Used in MySQL 5.1.5 to 5.1.17.
  • 17 — WRITE_ROWS_EVENT — row data for a single table

okay bestie, picking up right where we left off with the event type codes — here are the last few, no skips, no cap:

  • 18 — UPDATE_ROWS_EVENT — row data for a single table that needs to be updated. Used in MySQL 5.1.18 and later. 💅
  • 19 — DELETE_ROWS_EVENT — row data for a single table that should be deleted. Used in MySQL 5.1.18 and later.
  • 1a — INCIDENT_EVENT — something out of the ordinary happened. Added in MySQL 5.1.18. 🫣
  • Master ID — the server ID of the master that created the event. 👑
  • Size — the size in bytes of the event.
  • Master Pos — the position of the next event in the original master log file. 📍
  • Flags — 16 flags. Currently, the following flags are used. The others are reserved for future use. ✨
    • 01 — LOG_EVENT_BINLOG_IN_USE_F — the label literally says “Log file correctly closed.” (used only in FORMAT_DESCRIPTION_EVENT). And then the fine print flips it: if this flag is set (if the flags are, for example, '01 00') in a FORMAT_DESCRIPTION_EVENT, the log file has not been properly closed. Most probably this is because of a master crash (for example, due to power failure). 😭💀
    • 02 — (no name) — reserved for future use. 🙈
    • 04 — LOG_EVENT_THREAD_SPECIFIC_F — set if the event is dependent on the connection it was executed in (for example, '04 00'), for example, if the event uses temporary tables. 🧚
    • 08 — LOG_EVENT_SUPPRESS_USE_F — set in some circumstances when the event is not dependent on the default database. 🌸

🎀 MARIADB-BINLOG ROW EVENT DISPLAY 🎀

okay bestie, this next bit is the good part — like, the part where you actually get to see what changed in your data. ✨ The examples below show how mariadb-binlog displays row events that specify data modifications. These correspond to events with the WRITE_ROWS_EVENT, UPDATE_ROWS_EVENT, and DELETE_ROWS_EVENT type codes. And listen — the --base64-output=DECODE-ROWS and --verbose options may be used to affect row event output. 🫶

Suppose that the server is using row-based binary logging and that you execute the following sequence of statements:

CREATE TABLE t
(
  id   INT NOT NULL,
  name VARCHAR(20) NOT NULL,
  date DATE NULL
) ENGINE = InnoDB;
START TRANSACTION;
INSERT INTO t VALUES(1, 'apple', NULL);
UPDATE t SET name = 'pear', date = '2009-01-01' WHERE id = 1;
DELETE FROM t WHERE id = 1;
COMMIT;

By default, mariadb-binlog displays row events encoded as base-64 strings using BINLOG statements. Omitting extraneous lines, the output for the row events produced by the preceding statement sequence looks like this:

shell> mariadb-binlog log_file
...
# at 218
#080828 15:03:08 server id 1  end_log_pos 258     Write_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAANoAAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBcBAAAAKAAAAAIBAAAQABEAAAAAAAEAA//8AQAAAAVhcHBsZQ=='/*!*/;
...
# at 302
#080828 15:03:08 server id 1  end_log_pos 356     Update_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAC4BAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBgBAAAANgAAAGQBAAAQABEAAAAAAAEAA////AEAAAAFYXBwbGX4AQAAAARwZWFyIbIP'/*!*/;
...
# at 400
#080828 15:03:08 server id 1  end_log_pos 442     Delete_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAJABAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBkBAAAAKgAAALoBAAAQABEAAAAAAAEAA//4AQAAAARwZWFyIbIP'/*!*/;

ngl, that base-64 is giving unreadable 💀 so let's fix it. To see the row events as comments in the form of “pseudo-SQL” statements, run mariadb-binlog with the --verbose or -v option. The output will contain lines beginning with ###:

shell> mariadb-binlog -v log_file
...
# at 218
#080828 15:03:08 server id 1  end_log_pos 258     Write_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAANoAAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBcBAAAAKAAAAAIBAAAQABEAAAAAAAEAA//8AQAAAAVhcHBsZQ=='/*!*/;
### INSERT INTO test.t
### SET
###   @1=1
###   @2='apple'
###   @3=NULL
...
# at 302
#080828 15:03:08 server id 1  end_log_pos 356     Update_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAC4BAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBgBAAAANgAAAGQBAAAQABEAAAAAAAEAA////AEAAAAFYXBwbGX4AQAAAARwZWFyIbIP'/*!*/;
### UPDATE test.t
### WHERE
###   @1=1
###   @2='apple'
###   @3=NULL
### SET
###   @1=1
###   @2='pear'
###   @3='2009:01:01'
...
# at 400
#080828 15:03:08 server id 1  end_log_pos 442     Delete_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAJABAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBkBAAAAKgAAALoBAAAQABEAAAAAAAEAA//4AQAAAARwZWFyIbIP'/*!*/;
### DELETE FROM test.t
### WHERE
###   @1=1
###   @2='pear'
###   @3='2009:01:01'

Obsessed with this for you. 🌸 And if you specify --verbose or -v twice, you also display data types and some metadata for each column. The output will contain an additional comment following each column change:

shell> mariadb-binlog -vv log_file
...
# at 218
#080828 15:03:08 server id 1  end_log_pos 258     Write_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAANoAAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBcBAAAAKAAAAAIBAAAQABEAAAAAAAEAA//8AQAAAAVhcHBsZQ=='/*!*/;
### INSERT INTO test.t
### SET
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='apple' /* VARSTRING(20) meta=20 nullable=0 is_null=0 */
###   @3=NULL /* VARSTRING(20) meta=0 nullable=1 is_null=1 */
...
# at 302
#080828 15:03:08 server id 1  end_log_pos 356     Update_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAC4BAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBgBAAAANgAAAGQBAAAQABEAAAAAAAEAA////AEAAAAFYXBwbGX4AQAAAARwZWFyIbIP'/*!*/;
### UPDATE test.t
### WHERE
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='apple' /* VARSTRING(20) meta=20 nullable=0 is_null=0 */
###   @3=NULL /* VARSTRING(20) meta=0 nullable=1 is_null=1 */
### SET
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='pear' /* VARSTRING(20) meta=20 nullable=0 is_null=0 */
###   @3='2009:01:01' /* DATE meta=0 nullable=1 is_null=0 */
...
# at 400
#080828 15:03:08 server id 1  end_log_pos 442     Delete_rows: table id 17 flags: STMT_END_F
BINLOG 'fAS3SBMBAAAALAAAAJABAAAAABEAAAAAAAAABHRlc3QAAXQAAwMPCgIUAAQ=
fAS3SBkBAAAAKgAAALoBAAAQABEAAAAAAAEAA//4AQAAAARwZWFyIbIP'/*!*/;
### DELETE FROM test.t
### WHERE
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='pear' /* VARSTRING(20) meta=20 nullable=0 is_null=0 */
###   @3='2009:01:01' /* DATE meta=0 nullable=1 is_null=0 */

You can tell mariadb-binlog to suppress the BINLOG statements for row events by using the --base64-output=DECODE-ROWS option. This is similar to --base64-output=NEVER but does not exit with an error if a row event is found. 👑 The combination of --base64-output=DECODE-ROWS and --verbose provides a convenient way to see row events only as SQL statements:

shell> mariadb-binlog -v --base64-output=DECODE-ROWS log_file
...
# at 218
#080828 15:03:08 server id 1  end_log_pos 258     Write_rows: table id 17 flags: STMT_END_F
### INSERT INTO test.t
### SET
###   @1=1
###   @2='apple'
###   @3=NULL
...
# at 302
#080828 15:03:08 server id 1  end_log_pos 356     Update_rows: table id 17 flags: STMT_END_F
### UPDATE test.t
### WHERE
###   @1=1
###   @2='apple'
###   @3=NULL
### SET
###   @1=1
###   @2='pear'
###   @3='2009:01:01'
...
# at 400
#080828 15:03:08 server id 1  end_log_pos 442     Delete_rows: table id 17 flags: STMT_END_F
### DELETE FROM test.t
### WHERE
###   @1=1
###   @2='pear'
###   @3='2009:01:01'
Note 🚨 You should not suppress BINLOG statements if you intend to re-execute mariadb-binlog output. fr fr, this one matters — read it twice.

The SQL statements produced by --verbose for row events are much more readable than the corresponding BINLOG statements. However — and this is the important part, bestie — they do not correspond exactly to the original SQL statements that generated the events. The following limitations apply:

  • The original column names are lost and replaced by @N, where N is a column number.
  • Character set information is not available in the binary log, which affects string column display:
    • There is no distinction made between corresponding binary and nonbinary string types (BINARY and CHAR, VARBINARY and VARCHAR, BLOB and TEXT). The output uses a data type of STRING for fixed-length strings and VARSTRING for variable-length strings.
    • For multi-byte character sets, the maximum number of bytes per character is not present in the binary log, so the length for string types is displayed in bytes rather than in characters. For example, STRING(4) will be used as the data type for values from either of these column types:
CHAR(4) CHARACTER SET latin1
CHAR(2) CHARACTER SET ucs2
  • Due to the storage format for events of type UPDATE_ROWS_EVENT, UPDATE statements are displayed with the WHERE clause preceding the SET clause.

Proper interpretation of row events requires the information from the format description event at the beginning of the binary log. Because mariadb-binlog does not know in advance whether the rest of the log contains row events, by default it displays the format description event using a BINLOG statement in the initial part of the output. 🦋

If the binary log is known not to contain any events requiring a BINLOG statement (that is, no row events), the --base64-output=NEVER option can be used to prevent this header from being written. slay. ✨

Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc., 2010-2025 MariaDB Foundation

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA or see http://www.gnu.org/licenses/.

🌈 NOTES 🌈

  1. Bug#42941 http://bugs.mysql.com/bug.php?id=42941

🫶 SEE ALSO 🫶

For more information, please refer to the MariaDB Documentation, available online at https://mariadb.com/docs/

👑 AUTHOR 👑

MariaDB Foundation (http://www.mariadb.org/).

and that's the whole page, bestie — you made it to the end 🎀💅 This lil' beauty is from MariaDB 11.8, dated 5 March 2025, and it's the MARIADB-BINLOG(1) man page. go forth and decode those rows, icon. 💜

📦 where this page comes from