PGConf.Russia 2023

We offer to your attention our experience in data migration and the Ora2PgCopy program written in Java for high-speed data transfer from Oracle to Postgres, which is used after creating tables and transferring the program code of application systems. High data transfer speed is provided by using the Postgres command “copy”, using multithreaded Java technology for file processing, managing the nologged/logged table option, and supporting LOB and CLOB data types. According to the test results, Ora2PgCopy works noticeably faster than such analogues as: Ispirer (convertum), oracle_fdw, ora2pg, Pentaho kettle. Ora2PgCopy can function as a module as part of the LUI4ORA2PG migration automation system or independently of it. The history of the growth of the Live Universal Interface (LUI) web application development tool and the LUI4ORA2PG migration tool can be found in previous presentations at PGConf conferences: https://pgconf.ru/2019/118109 , https://pgconf.ru/201911/264095 , https://pgconf.ru/2020/262456, https://pgconf.ru/2021/288310, https://pgconf.ru/2022/316022.

There is set of Ansible roles for any Postgres configuration: a standalone instance; a streaming replica; patroni+etcd; stolon+etcd; patroni+consul; stolon+consul. In this talk, we will discuss why using this set of Ansible roles is better than other solutions.

One of the main problems when migrating from Oracle to PostgreSQL is PL/SQL packages.

The PostgreSQL DBMS lacks such functionality - this leads to the need to rewrite (up to its redesign!) the Oracle PL/SQL code to PL/pgSQL.

With the new version of its flagship Postgres Pro 15 Enterpise distribution, Postgres Pro has added support for package functionality: the PL/pgSQL syntax has been extended and new mechanisms have been added to the stored procedure runtime environment. The report will focus on supporting the functionality of packages in Postgres Pro 15 Enterpise: - grouping types of variable procedures and functions into a package; - support for the package initialization section; - support for global package variables available throughout the "life" of the session.

This presentation will also discuss the features of migration of packages from Oracle to Postgres Pro Enterprise DBMS.

This report is primarily intended for companies, specifically their IT departments, that are running Russian systems 1C 8.x and have the ability to work with both MSSQL Server and PostgreSQL. We live in a unique time when having a heterogeneous IT system (a system with a distributed architecture where each database instance runs under different databases and/or has a different data structure) is justified both economically and in terms of potential risks. On the one hand, we store data and use databases with predictable behavior and open source code, regardless of the political situation. On the other hand, with this approach, we take advantage of all the benefits (primarily performance) of a powerful database supported by the largest vendor, albeit a hostile state to us. Now is the time to assess risks with the necessary level of paranoia. After all, data can be corrupted not only at the level of storage logic, but also by the method of additional "hidden" calls of Delete/Update constructs at the engine level of the database. Therefore, it is now relevant not only to monitor the performance of the IT system, but also to audit data and their timely integrity. It is necessary to implement data verification procedures, it is necessary to implement procedures for closing periods, procedures for fault-tolerant storage. And accordingly, to provide for various threat models in data recovery procedures. The report presents options for countering such threats and scenarios for the most seamless transition of large databases to PostgreSQL, since it is precisely for such databases that the problem of translating to a new DBMS is particularly acute.