PostgreSQL Heap Only Tuple - HOT (Reducing Index Writing IO Enlargement Introduced by UPDATE)

Label PostgreSQL , Heap Only Tuple , HOT background PostgreSQL's current default storage engine generates a new version in the heap when updating records. The old version needs to recycle all index POINT associated with this version before it needs to recycle the old version after VACUUM is used. The KEY of the index of PG is the value of th ...

Posted by Goins on Mon, 06 May 2019 12:45:03 +0200

When configuring relational mapping in 3.2, the table names are different from those in 3.1.

Chapter 3.2 describes the mapping relationship of the corresponding classes according to the steps in the book. It is found that at startup, all the tables previously built in Chapter 3.1 were deleted and re-established, and the data of Ingredient table was lost. Because of the use of JPA, hibernate was used by default, all tables were deleted ...

Posted by axiom82 on Mon, 06 May 2019 04:50:03 +0200

PHP Full Stack Learning Notes 19

image.png The thinkphp framework is a free, open source, fast and simple object-oriented lightweight PHP development framework. Learn what is ThinkPHP overview, the directory structure of ThinkPHP projects, the controller of thinkphp, views, the process of building ThinkPHP projects, the configuration of thinkphp, the model o ...

Posted by betazoid on Mon, 06 May 2019 02:50:03 +0200