PgConf.Russia 2017

< Query failed: ERROR: deadlock detected
< DETAIL: Process 17371 waits for ShareLock on transaction 102733872; Blocked by process.
< Process 10414 waits for ShareLock on transaction 102733874; Blocked by process 17371.

Such "unpleasant" messages from the server can seriously puzzle the developer. When working with locks, in particular, with transactions in general, it is necessary to take into account the features of the implementation of client libraries, which can cause the above exception.

In the short talk, the mechanics of the interaction of locks will be explained, main attention being paid to causes of deadlocks. References to the relevant documentation pages will be given. A technique of "bypassing" this problem of concurrent data access will be described and illustrated with some generalized examples from practice are shown. The talk will be interesting to database developers and administrators as well as the client-side application developers.

1. What is an autonomous transaction?
2. An overview of autonomous transactions in "big" DBMS: Oracle.
3. Autonomous transaction logic in Postgres Pro.
4. An overview of emulation methods for autonomous transactions in PostgreSQL.
5. Comparing performance of the built-in Postgres Pro autonomous transaction mechanism and PostgreSQL emulation methods.

VIDEO

1. 1C:Enterprise 8 and PostgreSQL 9 interoperability 1.1 Changes in new 1C platform versions 1.2 v81c_data and v81c_index schemas 1.3 Sending 1C queries to SQL 1.4 Using 1C technological log events for PostgreSQL diagnostics
2. Analyzing queries that affect PostgreSQL performance 2.1 A free tool for automating log parsing 2.2 Pareto principle in action 2.3 Installation and configuration of the tool 2.4 A case study of query optimization 2.4.1 An issue in a PostgreSQL query 2.4.2 Finding non-optimal operations in a query 2.4.3 Resolving inefficiencies
3. PostgreSQL statistics for performance diagnostics 3.1 Comparing Postgres with MS SQL Server 3.2 Troubleshooting locks 3.3 Operating load diagnostics 4 Case studies by the gilev.ru team