Как переносить данные из Oracle в PostgreSQL и обратно

PostgreSQL has become a reality in a lot of shops today. In most cases PostgreSQL is established beside the current Oracle deployment and quite soon one question pops up regularily: How can we push data from Oracle to PostgreSQL and vice versa? Way back, in March 2001, a new extension to the SQL standard made it's way to define common APIs for managing external data: SQL/MED (ISO/IEC 9075-9:2008). The PostgreSQL community picked that up quite fast and implemented a framework for plugging in so called foreign data wrappers back in 2011 with PostgreSQL 9.1. Since then a wide range of these foreign data wrappers popped up and thanks to those, PostgreSQL today is able to integrate data from almost every external source, no matter if it is coming from flat files, other relational database systems or even unstructured sources. In this talk we will look at the foreign data wrapper for Oracle and how it can be used to get data from Oracle to PostgreSQL. But this is not a one way game: data can also be pushed from PostgreSQL to Oracle, and this might become important depending on the requirements. It is guaranteed that this talk is splitted by half: Slides and a lot of demos.

Построение автоматического консультанта и инструментов настройки производительности в PostgreSQL

PostgreSQL is a mature and robust RDBMS since it has 30 years of history. Over the year, its query optimizer has been enhanced and usually produces good query plans.

However, can it always come up with good query plans? The optimization process has to use some assumptions to produce plans fast enough. Some of those assumptions are relatively easy to check (e.g. statistics are up-to-date), some harder (e.g. correct indexes are created), and some nearly impossible (e.g. making sure that the statistic samples are representative enough even for skewed data repartition). For now, given those various caveats, DBA sometimes can't always realize easily that they miss a chance to get a meaningful performance improvement.

To help DBA to get a truly good query plan, we'll present below some tools that can help to fix some of those problems by providing a missing index adviser, looking for extended statistics to create, and row estimation error correction information to get appropriate join orders with join methods automatically.

• pg_qualstats: provides a new index and extended statistics suggestions to gather many predicate statistics on the production workload.
• pg_plan_advsr: provides alternative good query plans automatically to analyze iterative query executions information to fix estimation rows error.

In this talk, we will explain how those tools work under the hood and see what can be done, how they can work together. Also, we will mention what other tools also exist for related problems. Therefore, it will be useful for DBA who are interested in improving query performance or want to check whether current settings of indexes and statistics are adequate.

PostgreSQL и стандарты SQL

PostgreSQL is one of the most standards-compliant databases available. Talk discusses the impact that PostgreSQL has made on the SQL Standard and the features PostgreSQL has implemented from the SQL Standard, as well as upcoming features in PG14 and beyond.

Как использовать pspg

pspg is unix pager specially developed for usage in psql Postgres client. Today it allows more than usual browsing data. It can work in application mode or it work as csv or tsv viewer too. I will try to show the main possibilities of this application.