At TiDB DevCon2018, we announced the TiDB source code reading and sharing activity, and promised to publish a series of articles and videos to help everyone understand the TiDB source code. Everyon
Month: September 2021
PostgreSQL – Postgres Query Optimization
Below are two almost identical postgres queries, but produced very different query plans and execution times. I assume that the first query is fast because form_id =’W40′ is only 196 Form_instance
PostgreSQL – Reset ID count after table deletion ()
For testing purposes, I clear (delete) each table before executing the code.
for table in reversed (db.metadata.sorted_tables):
engine.execute(table.delete())
do_stuff() However, the id valu
NOSQL – Cassandra column key automatically increment
I am trying to understand Cassandra and how to build my column family (CF), but since I am used to relational databases, it is difficult.
For example , If I create a simple user CF and I try
Running errors in PostgreSQL
CREATE OR REPLACE FUNCTION msgfailerror() RETURNS trigger AS
‘ BEGIN
IF NEW.noces< new.first_column THEN
RAISE EXCEPTION ' cannot have a negative salary';
END IF;
return new;
END' LANGUAG
PostgreSQL – PLPGSQL function returns another function value
I have a function func1() that returns integers.
I want to write another function func2 (mode integer), which can return func1()reults Or do more things. The return value of func1() is INTEGE
Add a missing monthly date in the time series data in PostgreSQL
I have monthly time series data in the table, where the date is the last day of the month. Some dates are missing in the data. I want to insert these dates and add zero values for other attribute
Why is NOSQL better “expand” than RDBMS?
I discussed the advantages and disadvantages of NoSQL in the technical blog, and have read the following content
”
For many years, in order to improve the database server Performance, databas
Axure flowchart
What is a flow chart A flow chart can be used to show various processing flows, including use case flow, business flow, page flow, etc. In Axure, flowcharts are often used to provide a high-fidelit
BizTalk Plane File Architecture – How to Accept LF or CRLF as a line separator
Our client sends us a flat file as input, and then we convert it to an XML file before sending to the target system.
Flat The file consists of multiple lines, and each line is separated by LF