NoSQL databases are becoming popular day by day. I have come up with the list of best, free and open source NoSQL databases. MongoDB tops the list of Open Source NoSQL databases. This list of free and open source databases comprises of MongoDB, Cassandra, CouchDB, Hypertable, Redis, Riak, Neo4j, HBASE, Couchbase, MemcacheDB, RevenDB and Voldemort. These free and open source NoSQL databases are really highly scale-able, flexible and good for big data storage and processing. These open source NoSQL databases are far ahead in terms of performance as compared to traditional relational databases. However, these may not be always the best choice for you. Most of common applications can still be developed using traditional relational databases. NoSQL databases are still not the best option for a mission critical transaction needs. I have listed down a small description of all these best free and oper source NoSQL databases. Lets have a look.. 1. MongoDB MongoDB ...
This article comprises the FAQs related to salesforce internal platform Query Optimizer.and provides valuable information that will help understand how to improve the performance of SOQL queries. For more information, you may also check this Dreamforce Session . 1. Query Optimizer Q: Does Salesforce have its own SQL optimization logic instead of Oracle's built-in? A: Force.com is a multi-tenant platform. To consider multitenant statistics, the platform has its own SOQL query optimizer that determines optimal SQL to satisfy a specific tenant's request. Q: How frequently generated are the statistics used by the query optimizer? A: Statistics are gathered weekly. Where statistics are not calculated, the optimizer also performs dynamic pre-queries, whose results are cached for 1 hour Q: Is there any way to flush the cache when doing your performance testing so your results are not cached biased? A: Unfortunately not. Queries with selective filters will perform mor...