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sql execution statement flow analysis The whole processing flow is in exec_simple_query function. The code structure is as follows: /* * exec_simple_query * * Execute a "simple Query" protocol message. */ static void exec_simple_query(const char *query_string) { ... //Original syntax tree acquisition /* * Do basic parsing of the quer ...

sql execution statement flow analysis The whole processing flow is in exec_simple_query function. The code structure is as follows: /* * exec_simple_query * * Execute a "simple Query" protocol message. */ static void exec_simple_query(const char *query_string) { ... //Original syntax tree acquisition /* * Do basic parsing of the quer ...

Syntax analysis of PG database 1, Lexical analysis of gram.y The lexical parser is explained in the src\backend\parser\gram.y file. %{ Declarations %} Definitions %% Productions %% User subroutines In the lexical parser, we talked about the knowledge of. y files. This article mainly explains how to use the lexical parser in PG. 1,Declarat ...

2021SC@SDUSC catalogue Hash index In addition to using B-Tree index, postgreSQL can also use hash index. Hash index has faster query speed. This article mainly explains the principle of hash index, compares it with B-Tree, and analyzes the relevant data structure of hash index in the source code. Hash indexing principle Hash table The ...

Author: Zhang Lianzhuang, PostgreSQL R & D EngineerHe has been engaged in the development of PostgreSQL database kernel for many years and has a very in-depth research on citus.Recovering lost data quickly is an important functional requirement of the database. It is generally recommended to use the tools recommended by the official. For op ...

preface The company recently switched from Mysql to CockroachDB, so some problems encountered during this period are recorded here 1 development environment CockroachDB version V20.2.3 maven needs to introduce dependencies <dependency> <groupId>org.postgresql</groupId> <artifactId>postgresql</artifact ...

1. Select installation package The source file directory can be found in the official of postgresql. The address is as follows: Official website address of postgresql , select the corresponding version for installation according to the project requirements, as shown in the figure below: 2. Installation ① Unzip the installation package First, ...

Absrtact: using SQL as the entry of data query and analysis is an idea of data full stack. This article is shared from Huawei cloud community< How to use SQL to analyze data? >, author: zuozewei. preface We process user data in real time through OLTP (online transaction processing) system, and we also need to analyze them in OLAP ( ...

preface Recently, a customer of the company used PostgreSql to store data. In the export function, it was found that in the case of big data, the memory will grow until it overflows. Because the fetchSize is set for stream query in the export function, there will be no memory overflow. Then the investigation found that all the data were obtain ...

Docker configures the master-slave environment of PostgreSQL13 preface PostgreSQL database supports a variety of replication solutions to build high availability, scalable and fault-tolerant applications, one of which is pre write log (WAL) delivery. This solution allows the use of file based log shipping or streaming replication, or, wher ...