General database role privilege handling in SQL Server Recently, we have been doing database privilege cleanup with colleagues, mainly by deleting some accounts, removing the larger privileges of some accounts, etc. For example, some have db_owner privileges, we remove the database role db_owner of the accounts and grant the minimum required ...
Added by Karpathos on Wed, 15 May 2019 18:59:55 +0300
I have something to say:
After completing the data display function, I want to improve the whole APP. It is found that the background is very chaotic, and there are many points that are not available. For example, the picture should have thumbnails and original pictures, paragraphs, comments and comments should be linked together, paragraphs sh ...
Added by gordo2dope on Wed, 15 May 2019 17:30:51 +0300
As you all know, there are always some novel that is refreshing, whether it is fairy-man or fantasy. The first dozen chapters successfully circled a large wave of fans, successfully climbed the soaring list, hot list and other lists, throwing a few chestnuts out:
As a developer, it is particularly important to have a lea ...
Added by eabigelow on Wed, 15 May 2019 12:37:31 +0300
PostgreSQL, brin index, gin index, merge delay, gin_pending_list_limit, query performance degradation
GIN index is an inverted index of PostgreSQL database with multi-value type. A record may involve KEY in multiple GIN indexes. So if index is merged in real time when writing, IO will increase sharply and RT will increase in ...
Added by hatching on Wed, 15 May 2019 09:30:25 +0300
1. Installation environment
CentOS 6.8 Virtual Machine Three
1G per memory
50G per hard disk
2. Installation packages required
CDH5.9.0 Installation Package Files included: Parcel contains files:
Files included in rpms:
Before you start the installation below, make sure the number of files is correct
3. Installation steps
Added by robman2100 on Wed, 15 May 2019 09:27:31 +0300
We've already talked about it Principle and algorithm of MySQL InnoDB index Here's how to manage and use B+tree indexes and some new features.
Management of B+Tree Index
The basic indexes we use in the InnoDB engine are B+tree indexes.
Create and delete indexes
It can be created and deleted in two ways:
# Mode 1: alter table, in which case bot ...
Added by ehhwan on Wed, 15 May 2019 05:12:03 +0300
1. Install the database
If necessary, update the yum package management first. Take the CentOS system as an example below:
$ yum -y update
1. Install Mongodb
View the current system version
$ cat /etc/redhat-release
open https://repo.mongodb.org/yum/... , select the mongo version that suits your system, and then edit the Mongodb installation so ...
Added by Rianna on Wed, 15 May 2019 00:05:10 +0300
IpRateLimitMiddleware(Github: AspNetCoreRateLimit ) is a stream-limiting middleware for ASPNETCore that controls how often clients invoke APIs. If clients frequently access the server, it can limit its frequency and reduce the pressure of accessing the server.Or if a crawler is crawling critical data, you can limit the number of ca ...
Added by dapuxter on Tue, 14 May 2019 20:08:52 +0300
PostgreSQL, pgbench, tpcb, tpcc, tpch, lvm2, zfs, bands
Several recent PostgreSQL OLTP and OLAP tests:
PostgreSQL 11 tpcc Test (103,000 tpmC on ECS) - use sysbench-tpcc by Percona-Lab
(TPC-H test SF=10,SF=200) PostgreSQL 11 vs 10 vs Deepgreen
PostgreSQL 10 billion tpcb performance on ECS
PostgreSQL on Aliyun ECS + ESSD - 100 ...
Added by stanleycwb on Tue, 14 May 2019 14:43:51 +0300
Just using cloud development, I don't know if there are nested query statements in the small program database, so I can only use the most clumsy method to find out the loop and look up again. Okay, next, the question is, have you found out, what kind of value you found? I've been working on this problem for a day. I just starte ...
Added by james_andrews on Tue, 14 May 2019 14:10:23 +0300