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Fastest Aggregate function when you have series of duplicate values

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}

0

Frequently, I'll need to crunch down a table into a series of aggregates.

And frequently, it will look like this.

John, Smith, Houston, Texas, Order 55, Balloon, 99 dollars

John, Smith, Houston, Texas, Order 55, Bicycle, 400 dollars

In other words, there's the "key column" to group by (order ID in this case).

There's then columns that should be "summed" or "counted" or properly aggregated.

Then there's a bunch of columns that are just duplicated values. This happens a lot and is not necessarily a normalization problem (or you're querying a database like this anyway that you don't admin).

Seems like there's a few choices here. Max(blah), max(ha) max(whatver).

Or min(every column). Obviously since they're all the same, it'll return it.

There's also "group by" each of those duplicate columns. Naturally, this can provide different results depending on your assumptions/ certainty that the columns will be duplicated.

Then there's also, in MySQL only (not MS or Oracle) -- putting nada, and it'll just take the first row found.

Which is typically the fastest? I suppose the best way is to test it. Just wondering though.

sql-server performance query

share

asked 53 secs ago

user45867user45867

6192819

add a comment | 

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Frequently, I'll need to crunch down a table into a series of aggregates.

And frequently, it will look like this.

John, Smith, Houston, Texas, Order 55, Balloon, 99 dollars

John, Smith, Houston, Texas, Order 55, Bicycle, 400 dollars

In other words, there's the "key column" to group by (order ID in this case).

There's then columns that should be "summed" or "counted" or properly aggregated.

Then there's a bunch of columns that are just duplicated values. This happens a lot and is not necessarily a normalization problem (or you're querying a database like this anyway that you don't admin).

Seems like there's a few choices here. Max(blah), max(ha) max(whatver).

Or min(every column). Obviously since they're all the same, it'll return it.

There's also "group by" each of those duplicate columns. Naturally, this can provide different results depending on your assumptions/ certainty that the columns will be duplicated.

Then there's also, in MySQL only (not MS or Oracle) -- putting nada, and it'll just take the first row found.

Which is typically the fastest? I suppose the best way is to test it. Just wondering though.

sql-server performance query

share

asked 53 secs ago

user45867user45867

6192819

add a comment | 

Frequently, I'll need to crunch down a table into a series of aggregates.

And frequently, it will look like this.

John, Smith, Houston, Texas, Order 55, Balloon, 99 dollars

John, Smith, Houston, Texas, Order 55, Bicycle, 400 dollars

In other words, there's the "key column" to group by (order ID in this case).

There's then columns that should be "summed" or "counted" or properly aggregated.

Then there's a bunch of columns that are just duplicated values. This happens a lot and is not necessarily a normalization problem (or you're querying a database like this anyway that you don't admin).

Seems like there's a few choices here. Max(blah), max(ha) max(whatver).

Or min(every column). Obviously since they're all the same, it'll return it.

There's also "group by" each of those duplicate columns. Naturally, this can provide different results depending on your assumptions/ certainty that the columns will be duplicated.

Then there's also, in MySQL only (not MS or Oracle) -- putting nada, and it'll just take the first row found.

Which is typically the fastest? I suppose the best way is to test it. Just wondering though.

sql-server performance query

share

asked 53 secs ago

user45867user45867

6192819

John, Smith, Houston, Texas, Order 55, Balloon, 99 dollars

John, Smith, Houston, Texas, Order 55, Bicycle, 400 dollars

share

asked 53 secs ago

user45867user45867

6192819

share

asked 53 secs ago

user45867user45867

6192819

asked 53 secs ago

user45867user45867

6192819

asked 53 secs ago

user45867user45867

6192819