Tag:Partition table

  • How to deal with high water mark in Oracle Database

    Time:2021-5-11

    1、 What is a high water mark? When Oracle database creates a table, it will allocate a segment for the table. For the convenience of understanding, the upper limit of the segment space to hold data is called high water mark (HWM). HWM is a mark to indicate how many unused blocks are allocated to […]

  • Exploration of MySQL partition table

    Time:2021-5-8

    background If you need to regularly clean up the historical data in an ordinary large table. You can use one or more delete statements with a where condition (where condition is time). If the amount of table data is large, it will cause great pressure on the database. Even if we delete the old data, […]

  • Get to the point! Five key points of DWS development

    Time:2021-4-6

    Abstract:Efficient use of database is a necessary skill for a qualified development engineer. How to use DWS for efficient development and improve application efficiency? Here comes the technology~~~ Efficient use of database is a qualified Development Engineer’s necessary skills, how to use DWS for efficient development, improve application efficiency, the following five points can guide […]

  • SQL server according to the partition table name to find the file and file group implementation script

    Time:2021-3-29

    SELECT ps.name AS PSName, dds.destination_idAS PartitionNumber, fg.name AS FileGroupName,fg.name, t.name, f.name as filename FROM (((sys.tables AS t INNER JOIN sys.indexes AS i ON (t.object_id = i.object_id)) INNER JOIN sys.partition_schemes AS ps ON (i.data_space_id = ps.data_space_id)) INNER JOIN sys.destination_data_spacesAS dds ON (ps.data_space_id = dds.partition_scheme_id)) INNER JOIN sys.filegroups AS fg ONdds.data_space_id =fg.data_space_id innerjoin sys.database_files f on f.data_space_id […]

  • Linux knowledge

    Time:2021-3-25

    Basics The five units of a computer include:input unit 、output unit 、control unit 、arithmetic logic unit 、Storage unitTop fivepart. The CPU occupies the control and arithmetic logic unit, and the storage unit contains memory and auxiliary memory; Unit of measurement Carry system Kilo Mega Giga Tera Peta Exa Zetta Binary 1024 1024K 1024M 1024G 1024T […]

  • MySQL learning notes (14): partition

    Time:2021-3-5

    This article is updated on June 30, 2019, using MySQL 5.7 and operating system deepin 15.4. catalog Partition type Range partition List partition Columns partition Hash partition Key partition Subarea Partition management Partition management of range partition and list partition Partition management of hash partition and key partition Partition type have access toSHOW PLUGINSCheck to […]

  • MySQL partition

    Time:2021-2-26

    MySQL partition Advantages of partitioning Store more data To optimize the query, only scan one or more necessary partitions. For count () and sum (), only summarize the partition statistics For data that is out of date or does not need to be saved, partitioning is faster Data queries are distributed across multiple disks to […]

  • MySQL partition

    Time:2021-2-26

    MySQL partition Advantages of partitioning Store more data To optimize the query, only scan one or more necessary partitions. For count () and sum (), only summarize the partition statistics For data that is out of date or does not need to be saved, partitioning is faster Data queries are distributed across multiple disks to […]

  • SQL optimization in partition table scenario

    Time:2021-1-10

    Reading guide A table is partitioned, one partition per day. There is a query on the table. It often only queries the data of a certain day in the table, but it almost scans all the data of the whole partition every time. Is there any way to optimize it? Scenarios to be optimized There […]

  • Range partition

    Time:2020-12-6

    Series articles: Range partition MySQL execution plan The partition method of range partition table is: each partition contains row data, and the partition expression is within the given range. The range of partition should be continuous and can not overlap, which can be defined by the values less than operator. Create common table 1 CREATE […]

  • Live review | Japanese engineer Amit langote talks about table partition in Postgres

    Time:2020-10-31

    Table partitioning is a set of techniques for handling large data, as well as convenient options for managing data. In short, dividing a large table into smaller tables that are easier to manage is called partitioning. On June 27, Beijing time, Amit langote, developer of PostgreSQL international community and engineer of EDB Japan company, was […]

  • hot wire! PostgreSQL 13 adds new features!

    Time:2020-10-23

    Number one: vacuum speed increased by 3 times For PostgreSQL novices, cleanup is part of a multi version concurrent system, which is responsible for deleting invalid tuples or rows that are generated whenever a record is changed or deleted. The autovacuum feature eliminates table bloating by removing dead (deleted) hidden rows, similar to Java’s garbage […]