PostgreSQL 8.1 Sensational release, I also intend to migrate some of the original SQL Server applications to PostgreSQL, the first need to migrate a table, then this must first understand the data types in the two database mapping relationship.
PostgreSQL Type
the default. NET type
specific types of offers
other. NET Types
bool
bool
Int2
Short
BYTE, sbyte, int, long, float, double, decimal, string
The amount of data will be huge in the future/you cannot predict the size of the data. We recommend that you change to PostgreSQL.
After a certain amount of data is stored in MySQL (generally, the performance of a single MySQL table is the best-,
PostgreSQL has a wide range of data types available. Users can use the CREATE type command to Add new data types to PostgreSQL. Table 8-1 shows all the built-in common data types. Most of the optional names listed in the aliases column are names
Tutorial on implementing recursive query in PostgreSQL, postgresql Recursion
Introduction
I am working on a program in nilint32 (Open Source !) It is used to design and initiate surveys.
The following is an example of a survey:
Internally, it
Test data of PostgreSQL running on FreeBSD and Linux
This afternoon I wanted to test DragonFly dports. I suddenly wondered why I didn't compare the performance difference between PostgreSQL in BSD and Linux. For this reason, I set some standards to
Join nodeThe Join node has the following three types: T_NestLoopState, T_MergeJoinState, T_HashJoinState,The connection type node corresponds to the join operation in the relational algebra, and the following connection types are defined in
Indexed by: Unique index, primary key index, multi-attribute index, partial index, expression index.Index type: b-tree,hash,gist,gin and expression indexPostgreSQL all indexes are "subordinate indexes", that is, the index is physically detached from
Tips for improving PostgreSQL Performance
In a (poor) PostgreSQL query, only a small change is required (ANY (ARRAY [...]). to ANY (VALUES (...))) the query time can be reduced from 20 s to 0.2 s. From the simplest use of explain analyze, to the use
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