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Why is SQL query slow the first time?
Whereas for a similar SQL Server database (with that same table in schema and size), it takes just 1 second the first time, the next times it reports 00:00:00 My customers want it faster but really it’s limited by their database/server.
Which is faster Oracle server or SQL Server?
I want Oracle server to somehow remove all unnecessary jobs while performing such a simple query the first time so that it works just as fast as the SQL Server (at least a bit around that execution time).
How long does it take to load 74 rows in Oracle?
Really the result shows me nothing new, just a black-box of table-access-full consuming 28 seconds to load just 74 rows (of course for the first time). The black-box I mean looks like this: The total time to run the test query is about 29.651 seconds, as you can see the black-box above consumes almost the time ( 28.97 seconds).
Is it slow to select from that table?
It is much slower than select * from that_table, really strange. UPDATE with tracing info : By using tkprof and some statement to enable tracing for the current session, I could obtain the trace-file, analyzed it into an output text file (using tkprof ).
How can I improve the performance of my SQL query?
You can improve your query efficiency by using a tool to analyze and optimize your SQL queries. SQL query planning tools look for performance problems and give you data to better understand how your queries are measuring up. Here’s the tip: ApexSQL Plan is a free SQL query planning tool that provides valuable information.
Is there such thing as super slow query syndrome?
Your boss calls it “sequel,” but you’ve been calling it S-Q-L for months. And that’s not the worst. You’re suffering from “Super Slow Query Syndrome,” and sometimes, your queries bomb without a result. Don’t worry.
How to slow down a query in Excel?
Using functions in a Where clause or Join clause can also slow down your query. For example, if you filter on an uppercase word, then the value in every row needs to be converted to uppercase to do the conversion:
How to improve the performance of an oracle query?
As a general rule, Oracle recommends that you collect statistics on your base table if you are interested in improving your query performance. The optimizer attempts to choose the best execution plan based on the following parameters: the selectivity on the CONTAINSpredicate the selectivity of other predicates in the query
How to optimize the response time in Oracle?
For example, consider the following PL/SQL block that uses a cursor to retrieve the first 10 hits of a query and uses the FIRST_ROWS(n)hint to optimize the response time: declare cursor c is select /* FIRST_ROWS(10) */ article_id from articles_tab where contains(article, ‘Oracle’)>0 order by pub_date desc; begin
How many rows does SQL Server expect to return?
Look at the execution plan, hover your mouse over the index seek, and you’ll see that SQL Server expected 5,305 rows – and 5,305 actually came back. Awesome. Now let’s try that query looking for Reputation = 1: Note that even though SQL Server auto-parameterized the query (that’s the @1 part at the top), SQL Server chose a different execution plan.