Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.0k views
in Technique[技术] by (71.8m points)

database - Is it faster to search for a large string in a DB by its hashcode?

If I need to retrieve a large string from a DB, Is it faster to search for it using the string itself or would I gain by hashing the string and storing the hash in the DB as well and then search based on that?

If yes what hash algorithm should I use (security is not an issue, I am looking for performance)

If it matters: I am using C# and MSSQL2005

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

In general: probably not, assuming the column is indexed. Database servers are designed to do such lookups quickly and efficiently. Some databases (e.g. Oracle) provide options to build indexes based on hashing.

However, in the end this can be only answered by performance testing with representative (of your requirements) data and usage patterns.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...