OracleGoldenGate's thought sky-understanding the essence of OGG
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Oracle GoldenGate's thought sky-understanding the essence of OGG
The title of this article is highly imitating Bai Zong's thought sky of DBA-understanding the essence of oracle Database.
This article describes your understanding of OGG, which may be incorrect. Thank you for your criticism.
1. OGG is a data synchronization software, or logic replication software. Its competitors include ibm cdc, DELL shareplex, DSG, and DDS.
2. OGG software must be installed on the operating system. Oracle DB software does not have its own OGG software (at least currently)
3. The OGG software has three major processes (the four major processes can also be said ):
Three processes: Source extraction process, source transmission process, and target application process (namely, replication process)
Four processes: the source extraction process, the source transmission process, the target server process (responsible for writing the trail file to the target), and the target application process (namely, the replication process)
4. OGG software has two types of trail file
Source trail file: written by the source extraction process.
Destination trail file: the source transmission process is transmitted to the destination, and the destination server process is written to the specified path of the destination operating system.
5. All three processes in OGG software have their own checkpoints (I .e., checkpoints are used to record the locations where each process reads and writes)
Source extraction process: there are read and write checkpoints
Source transmission process: there are read and write checkpoints
Target application process: there is a read checkpoint
6. Three major OGG software processes the trail file:
Source extraction process: Read the oracle redo log (assuming that the source database is oracle), and convert the content in the redo log into a file in OGG's own format (I .e: and write it to the specified path of the source operating system.
Source transmission process: read "The trail file written by the source extraction process", send the data to be synchronized to the target end in combination with the parameter file of the transmission process, the server process is responsible for writing data to the target end.
Target application process: Read the trail file in the specified path of the target operating system, combine the parameter files of the application process to form SQL statements, and execute these SQL statements on the target database.
