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How to control the deletion speed of SQL deletion rows

This article addresses optimizing SQL DELETE statement speed. Poorly executed DELETEs cause lock contention and performance issues. Solutions include batching, optimized WHERE clauses, transaction control, indexing, partitioning, temporary tables,

Mar 04, 2025 pm 05:51 PM

How to deal with large data volumes of SQL delete rows

This article tackles challenges of deleting large datasets in SQL. It highlights performance issues caused by table locking and transaction log bloat, advocating for strategies like batch deletion, indexing, and judicious transaction use. The artic

Mar 04, 2025 pm 05:50 PM

What is the difference between SQL delete rows and truncate

This article compares SQL's DELETE and TRUNCATE commands. DELETE removes rows individually, allowing conditional removal and transaction rollback. TRUNCATE is faster, removing all rows at once, but lacks rollback capability. Performance and data re

Mar 04, 2025 pm 05:49 PM

How to use script for SQL delete rows

This article explains how to delete rows from SQL databases using scripts. It covers DELETE statement syntax, automation using various scripting languages (Python, Bash, PowerShell), and best practices for data integrity, including backups, transact

Mar 04, 2025 pm 05:49 PM

How to use command line for SQL delete line

This article provides a comprehensive guide to deleting SQL rows via the command line. It details various methods using the DELETE statement, emphasizing efficiency through selective WHERE clauses and indexing. The article also highlights crucial b

Mar 04, 2025 pm 05:48 PM

How to optimize the performance of deleting SQL rows

This article addresses optimizing SQL DELETE performance. Slow DELETEs, especially on large datasets, severely impact database performance. The article advocates for using highly selective WHERE clauses, indexes (B-tree, clustered, non-clustered, a

Mar 04, 2025 pm 05:47 PM

How to avoid data loss by SQL deleting rows

This article addresses SQL row deletion and data loss prevention. It emphasizes meticulous planning, including pre-deletion data verification via SELECT statements, testing in staging environments, transaction use, and robust backup strategies (full

Mar 04, 2025 pm 05:47 PM

How to use AWS Glue crawlers with Amazon Athena

As a data professional, you deal with immense amounts of data from a variety of sources. This can make data management and analysis a challenge. Luckily, two AWS services can help: AWS Glue and Amazon Athena. When you integrate these services, yo

Oct 22, 2024 am 10:33 AM

sql

Detailed explanation of spark join strategy

This article discusses Apache Spark's join strategies to optimize join operations. It details the Broadcast Hash Join (BHJ), Sort Merge Join (SMJ), and Shuffle Hash Join (SHJ) strategies. The article emphasizes choosing the appropriate strategy based

Aug 15, 2024 pm 02:39 PM

Detailed explanation of psql library and schema

This article explains the differences between databases, schemas, and tables in PostgreSQL (psql), covering their roles and characteristics in hierarchical data organization. It also provides practical examples for creating, modifying, and managing s

Aug 15, 2024 pm 02:38 PM

Detailed explanation of TS (.d.ts) files

A TS(.d.ts) file (TypeScript Declaration File) provides type information about a module or library to the TypeScript compiler, allowing for type checking, code completion, and hinting during development. It aids in understanding variable, function, a

Aug 13, 2024 pm 03:55 PM

Kibana Query Language - KQL

Kibana Query Language (KQL) enables filtering and searching vast datasets. Despite its limitations in querying non-Elasticsearch sources and complexity, KQL offers various workarounds and complements Kibana features like visualizations and dashboards

Aug 13, 2024 pm 03:54 PM

Usage of rename in sql

The RENAME command is used in SQL to rename a table, column, or constraint. The syntax is: RENAME [object_type] old_name TO new_name;, where object_type specifies the object type (table, column, or constraint), old_name is the old name, and new_name is the new name. You need to pay attention to the following when renaming: the new name cannot be repeated with objects of the same type; when renaming a column, the column type cannot be changed; when renaming a constraint, the new name must comply with the constraint type rules; the RENAME command does not support cross-database renaming; recommendations Back up the table structure before using the RENAME command to prevent data loss.

May 09, 2024 am 09:36 AM

数据丢失

How to remove the decimal point from sum in sql

How to remove the decimal point of SUM in SQL: Use the ROUND() function: ROUND(SUM(expression), decimal_places) Keep 0 decimal places: ROUND(SUM(salary), 0) Round to the nearest integer The ROUND() function only affects the query The results show that the decimal point is permanently deleted without affecting the data in the table: ALTER TABLE employee ALTER COLUMN salary TYPE INT

May 09, 2024 am 09:33 AM