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How can I further optimize a derived table query which performs better than the JOINed equivalent?

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UPDATE: I found a solution. See my Answer below. My Question How can I optimize this query to minimize my downtime? I need to update over 50 schemas with the number of tickets ranging from 100,000 to 2 million. Is it advisable to attempt to set all fields in tickets_extra at the same time? I feel that there is a solution here that I'm just not seeing. Ive been banging my head against this problem for over a day. Also, I initially tried without using a sub SELECT, but the performance was much worse than what I currently have. Background I'm trying to optimize my database for a report that needs

Create a SQL query to retrieve most recent records

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I am creating a status board module for my project team. The status board allows the user to to set their status as in or out and they can also provide a note. I was planning on storing all the information in a single table ... and example of the data follows: Date User Status Notes ------------------------------------------------------- 1/8/2009 12:00pm B.Sisko In Out to lunch 1/8/2009 8:00am B.Sisko In 1/7/2009 5:00pm B.Sisko In 1/7/2009 8:00am B.Sisko In 1/7/2009 8:00am K.Janeway In 1/5/2009 8:00am K.Janeway In 1/1/2009 8:00am J.Picard Out Vacation I would like to query the data and return

How can I further optimize a derived table query which performs better than the JOINed equivalent?

阅读更多关于 How can I further optimize a derived table query which performs better than the JOINed equivalent?

问题 UPDATE: I found a solution. See my Answer below. My Question How can I optimize this query to minimize my downtime? I need to update over 50 schemas with the number of tickets ranging from 100,000 to 2 million. Is it advisable to attempt to set all fields in tickets_extra at the same time? I feel that there is a solution here that I'm just not seeing. Ive been banging my head against this problem for over a day. Also, I initially tried without using a sub SELECT, but the performance was much

Create a SQL query to retrieve most recent records

阅读更多关于 Create a SQL query to retrieve most recent records

问题 I am creating a status board module for my project team. The status board allows the user to to set their status as in or out and they can also provide a note. I was planning on storing all the information in a single table ... and example of the data follows: Date User Status Notes ------------------------------------------------------- 1/8/2009 12:00pm B.Sisko In Out to lunch 1/8/2009 8:00am B.Sisko In 1/7/2009 5:00pm B.Sisko In 1/7/2009 8:00am B.Sisko In 1/7/2009 8:00am K.Janeway In 1/5

Create a temporary table in a SELECT statement without a separate CREATE TABLE

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问题 Is it possible to create a temporary (session only) table from a select statement without using a create table statement and specifying each column type? I know derived tables are capable of this, but those are super-temporary (statement-only) and I want to re-use. It would save time if I did not have to write up a create table command and keep the column list and type list matched up. 回答1: CREATE TEMPORARY TABLE IF NOT EXISTS table2 AS (SELECT * FROM table1) From the manual found at http:/