What does a DBA do in a new job?

In April 2014, I entered a new company. Before I entered the office, the company had no DBA, and the director gave me a task to optimize a business system.

So he gave me a little bit about the current situation:

1, the system database is often down.

2, the user often complained that the program does not respond.

I had two eyes and a smear, this can explain what the problem, the database has a lot of problems, this is my first reaction.

However, the work must go on, in the absence of information, do not understand the business situation,

In the first step, I started monitoring for up to one months:

1. The data collector is defined using Windows Performance Monitor.

2. Use SQLProfiler to crawl all SQL statements.

The second step, the analysis log:

1. Analyze server hardware bottleneck according to data collected by Data collector.

2, the SQLProfiler collected SQL statements into the local database, the use of full-text index of TSQL and stored procedures for statistical analysis.

Step Three:

1, submit hardware upgrade plan.

2. Reconfigure the database.

3, submit the optimization program.

One person took another 2 months to optimize the system, and finally the performance of the system improved greatly.

But I think the performance of the system has a lot of room to improve, but I encountered a problem, because of the system business logic does not understand,

Database performance cannot be radically improved, and modifying the database structure has a greater impact on the system and the company cannot afford it, so

It all stops here.

After that, the optimization of the company's other systems has made me feel deeply about the database design:

1, database design problems, no matter how to improve hardware performance, how to optimize, are useless.

2, optimization is the most easy to reflect the results of the index optimization.

3, optimization is omni-directional, not only need to know the TSQL statement optimization, index optimization and so on, the optimization of the system business logic is equally important.

4, the optimization starts from the big aspect, then cuts into the detail.

In addition, I have to thank the Birch, in the process of collecting data, I read his blog about full-text indexing, in the statistical TSQL statement information,

I used full-text indexing, which helped me a lot when I was parsing a TSQL statement.

What does a DBA do in a new job?