This chapter contains support information for Oracle GoldenGate on MySQL databases.
Topics:
Parent topic: Using Oracle GoldenGate with MySQL
MySQL provides a facility that allows users to specify different character sets at different levels.
Level | Example |
---|---|
Database |
create database test charset utf8; |
Table |
create table test( id int, name char(100)) charset utf8; |
Column |
create table test ( id int, name1 char(100) charset gbk, name2 char(100) charset utf8)); |
Limitations of Support
When you specify the character set of your database as utf8mb4/utf8, the default collation is utf8mb4_unicode_ci
/utf8_general_ci
. If you specify collation_server=utf8mb4_bin
, the database interprets the data as binary. For example, specifying the CHAR
column length as four means that the byte length returned is 16 (for utf8mb4) though when you try to insert data more than four bytes the target database warns that the data is too long. This is the limitation of database so Oracle GoldenGate does not support binary collation. To overcome this issue, specify collation_server=utf8mb4_bin
when the character set is utf8mb4 and collation_server=utf8_bin
for utf8.
The following character sets are not supported:
armscii8
keybcs2
utf16le
geostd8
Parent topic: Understanding What's Supported for MySQL
MySQL supports the following data types:
CHAR
VARCHAR
INT
TINYINT
SMALL
INT
MEDIUM INT
BIG INT
DECIMAL
FLOAT
DOUBLE
DATE
TIME
YEAR
DATETIME
TIMESTAMP
BINARY
VARBINARY
TEXT
TINYTEXT
MEDIUMTEXT
LONGTEXT
BLOB
TINYBLOB
MEDIUMBLOB
LONGBLOB
ENUM
BIT(M)
When running Oracle GoldenGate for MySQL, be aware of the following:
Oracle GoldenGate does not support BLOB
or TEXT
types when used as a primary key.
Oracle GoldenGate supports UTF8 and UCS2 character sets. UTF8 data is converted to UTF16 by Oracle GoldenGate before writing it to the trail.
UTF32 is not supported by Oracle GoldenGate.
Oracle GoldenGate supports a TIME
type range from 00:00:00 to 23:59:59.
Oracle GoldenGate supports timestamp data from 0001/01/03:00:00:00
to 9999/12/31:23:59:59
. If a timestamp is converted from GMT to local time, these limits also apply to the resulting timestamp. Depending on the time zone, conversion may add or subtract hours, which can cause the timestamp to exceed the lower or upper supported limit.
Oracle GoldenGate does not support negative dates.
The support of range and precision for floating-point numbers depends on the host machine. In general, the precision is accurate to 16 significant digits, but you should review the database documentation to determine the expected approximations. Oracle GoldenGate rounds or truncates values that exceed the supported precision.
When you use ENUM
type in non-strict sql_mode
, the non-strict sql_mode
does not prevent you from entering an invalid ENUM
value and an error will be returned. To avoid this situation, do one of the following:
Use sql_mode
as STRICT
and restart Extract. This prevents users from entering invalid values for any of the data types. An IE user can only enter valid values for those data types.
Continue using non-strict sql_mode
, but do not use ENUM
data types.
Continue using non-strict sql_mode
and use ENUM
data types with valid values in the database. If you specify invalid values, the database will silently accept them and Extract will abend.
To preserve transaction boundaries for a MySQL target, create or alter the target tables to the InnoDB transactional database engine instead of the MyISAM engine. MyISAM will cause Replicat records to be applied as they are received, which does not guarantee transaction integrity even with auto-commit turned off. You cannot roll back a transaction with MyISAM.
Extraction and replication from and to views is not supported.
Transactions applied by the slave are logged into the relay logs and not into the slave's binlog
. If you want a slave to write transactions the binlog
that it receives from the master , you need to start the replication slave with the log slave-updates option as 1 in my.cnf
. This is in addition to the other binary logging parameters. After the master's transactions are in the slave's binlog
, you can then setup a regular capture on the slave to capture and process the slave's binlog
.
Parent topic: Supported MySQL Data Types
Oracle GoldenGate for MySQL supports to following objects and operations:
Basic extraction and replication of DDL (data definition language) operations for MySQL 5.7.10 and later. Only the CREATE TABLE
, ALTER TABLE
, and DROP TABLE
operations are supported.
Oracle GoldenGate supports the extraction and replication of transactional tables.
Oracle GoldenGate supports transactional tables up to the full row size and maximum number of columns that are supported by MySQL and the database storage engine that is being used. InnoDB supports up to 1017 columns.
Oracle GoldenGate supports the AUTO_INCREMENT
column attribute. The increment value is captured from the binary log by Extract and applied to the target table in a Replicat insert operation.
Oracle GoldenGate supports the following DML operations on source and target database transactional tables:
Insert operation
Update operation (compressed included)
Delete operation (compressed included); cascade delete queries result in the deletion of the child of the parent operation
Truncate operation
Oracle GoldenGate can operate concurrently with MySQL native replication.
Oracle GoldenGate supports the DYNSQL
feature for MySQL.
Limitations on Automatic Heartbeat Table support are as follows:
Ensure that the database in which the heartbeat table is to be created already exists to avoid errors when adding the heartbeat table.
In the heartbeat history lag view, the information in fields like heartbeat_received_ts
, incoming_heartbeat_age
, and outgoing_heartbeat_age
are shown with respect to the system time. You should ensure that the operating system time is setup with the correct and current time zone information.
Heartbeat Table is not supported on MySQL 5.5.
Parent topic: Understanding What's Supported for MySQL
MySQL does not support the following data types:
The XML
, SET
, and Geometry data types and similar are not supported.
There is no support for the Interval data type.
Parent topic: Understanding What's Supported for MySQL