[ERROR] /usr/sbin/mysqld: Can’t find file: ‘./mysql/host.frm’ (errno: 13) [ERROR] Fatal error: Can’t open and lock privilege tables: Can’t find file: ‘./mysql/host.frm’ (errno: 13) We usually see above errors while we’re trying to start an additional MySQL instances on the…
[ root @ dbversity : /tmp ] [ root @ dbversity : /tmp ] ll -lhtr MySQL-5.6.25-1.el6.x86_64.rpm-bundle.tar -rw-r–r– 1 sm70768 mongod 213M Jun 22 08:25 MySQL-5.6.25-1.el6.x86_64.rpm-bundle.tar [ root @ dbversity : /tmp ] [ root @ dbversity : /tmp…
How Wired is MongoDB + WiredTiger? MongoDB 3.0 is a major release with long awaited improvements. The most notable? The optional storage engine WiredTiger. After all, WiredTiger was founded by the people behind Berkeley DB. MongoDB claims WiredTiger write performance…
A Technical Introduction to WiredTiger Document-level Concurrency In-memory performance Multi-core scalability Checksums Compression Durability with & without journaling MongoDB 3.0 introduces a new pluggable storage engine API and a new storage engine called WiredTiger. The engineering team behind WiredTiger…
[ root @ dbvesitydotcom : ~ ] mongo MongoDB shell version: 2.6.5 connecting to: test > > > use dbversity_db switched to db dbversity_db > > db.mycol.insert({L1F1:”val1″,L1F2:[{L2F1:”val2″,L2F2:”val3″,L2F3:[{L3F1:”val50″, L3F2:”val51″,L3F3:”val52″},{L3F1:”val53″, L3F2:”val54″,L3F3:”val55″}]},{L2F4:”val4″,L2F5:”val5″}]}) WriteResult({ “nInserted” : 1 }) > > > db.mycol.find().pretty() { …
[root@localhost apache2]# cat ../apache.py __author__ = ‘root’ #!/usr/bin/python import re import sys from datetime import datetime, date, timedelta from collections import Counter # Define the day of interest in the Apache common log format. try: daysAgo = int(sys.argv[1]) except:…
[root@localhost utils]# pwd /root/Documents/dbversity/utils [root@localhost utils]# [root@localhost utils]# [root@localhost utils]# ll -lhtr total 20K -rw-r–r–. 1 root root 0 Jun 8 14:24 _init_.py -rw-r–r–. 1 root root 95 Jun 8 14:35 new_function.py -rw-r–r–. 1 root root 77 Jun 8 14:54…
MongoDB has raced ahead of its NoSQL database competitors Cassandra and Couchbase for scalability, according to tests using the Yahoo Cloud Serving Benchmark (YCSB). The research, carried out by benchmarking and performance-testing firm United Software Associates (USA Inc), involved evaluating…
• A Document database • Developed by MongoDB Inc. • Latest version is 3.0.2 (released on April 9, 2015) • Runs on most platforms such as Red Hat Enterprise, CentOS, Fedora Linux, Ubuntu, Debian, Linux, OS X, Windows • Supports…