Introduction of Oracle Goldengate learning goldengate ____oracle

Goldengate TDM (transaction data management) software is a kind of structured data replication software based on log, which can be used to analyze and change the data from the online log or archive log of the source database, then apply these changes to the target database, and realize the synchronization and double live of the source database and target database. Goldengate TDM software enables real-time replication of a large amount of data in a heterogeneous IT infrastructure, including almost all common operating system platforms and database platforms, and its replication process is as follows:

As shown in the figure above, the data replication process for Goldengate TDM is as follows:

Using the capture process (Capture process) to read the online Redo log or archive log on the source system side, and then parse it, only extract the data changes such as adding, deleting and changing the operation, and converting the relevant information to Goldengate TDM's Custom intermediate format is stored in the queue file. The routing process is then used to transfer the queue files over TCP/IP to the target system. Capturing the process after each read data changes in the log and after the data is transferred to the target system, will write checkpoints, record the current completion of the capture log location, Checkpoint can make the capture process can be aborted and recovered from the checkpoint location to continue copying;

The target system accepts data changes and caches it into the Goldengate TDM queue, queues a series of files that temporarily store data changes, waiting for the delivery process to read the data;

The Goldengate TDM delivery process reads the data changes from the queue and creates the corresponding SQL statements, executes through the local interface of the database, updates its checkpoint after the database has been successfully submitted, records the location where the replication has been completed, and the data copy process is finally completed.

Thus, Goldengate TDM is a software-based method of data replication, which resolves data changes from the log of the database (the amount of data is only about One-fourth of the log). Goldengate TDM transforms data changes into its own format, directly via TCP/IP networks, without relying on the way the database itself is delivered, and compresses data by up to 9:1 compression, which can greatly reduce bandwidth requirements. On the target side, Goldengate TDM can greatly accelerate the speed and efficiency of data delivery by means of transaction reorganization, batch loading and so on, reduce the resource occupancy of the target system, and realize a large amount of data replication at the sub-second level, and the target-side database is active

Goldengate TDM provides a flexible application solution based on its advanced, flexible technology architecture that can be composed of a variety of topologies based on user requirements, as shown in the figure:

Goldengate TDM can provide reliable data replication, mainly in the following three points:

Ensure transactional consistency

Goldengate TDM in the disaster preparedness database The order of the replicated database transactions is the same as that in the Production Center database, and the same transaction environment is submitted to ensure the integrity and read consistency of the data on the target system, creating the conditions for real-time query and transaction processing.

checkpoint mechanism guarantees no loss of data

The Goldengate TDM extraction and replication process uses the checkpoint mechanism to record where replication is completed. For the extraction process, the checkpoint records the location of the currently extracted log and the location of the write queue file, and for the drop process, its checkpoint records the location of the currently read queue file. The checkpoint mechanism ensures that data is not lost after the system, network, or goldengate TDM process fails to restart.

reliable data transmission mechanism

Goldengate TDM transmits transaction data using the answering mechanism, and the data is automatically retransmitted only after the confirmation message is received, which ensures that all the extracted data can be sent to the backup end. 128-bit encryption and data compression are supported during data transfer.

Goldengate TDM can provide reliable data replication, mainly in the following three points:

Ensure transactional consistency

Goldengate TDM in the disaster preparedness database The order of the replicated database transactions is the same as that in the Production Center database, and the same transaction environment is submitted to ensure the integrity and read consistency of the data on the target system, creating the conditions for real-time query and transaction processing.

checkpoint mechanism guarantees no loss of data

The Goldengate TDM extraction and replication process uses the checkpoint mechanism to record where replication is completed. For the extraction process, the checkpoint records the location of the currently extracted log and the location of the write queue file, and for the drop process, its checkpoint records the location of the currently read queue file. The checkpoint mechanism ensures that data is not lost after the system, network, or goldengate TDM process fails to restart.

reliable data transmission mechanism

Goldengate TDM transmits transaction data using the answering mechanism, and the data is automatically retransmitted only after the confirmation message is received, which ensures that all the extracted data can be sent to the backup end. 128-bit encryption and data compression are supported during data transfer.

Oracle's goldengate product, which enables data capture, conversion, and delivery of a large amount of data between heterogeneous IT infrastructures. Goldengate can support almost all common operating systems such as and database platforms, as shown in the following table:

Operating system	Database
MS NT, 2000, XP, Linux, Sun Solaris, HP-UX, IBM AIX, HP Nonstop, TRU64, IBM z/os,os/390	Oracle, DB2, MS SQL Ser ver, MySQL, Enscribe, SQL/MP, Sql/mx, Sybase, Teradata, other ODBC-compliant databases