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237 views

How to organize the tables of a MySQL database with several statistics data of several years?

I am developing an app that must provide statistics information about the distribution of the money that a person spends each year in taxes in the city where he lives. The user should select the ...
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88 views

how to force oracle 12c to create histograms

I installed TPC-H on Oracle 12c and my goal is to get histograms on column groups (if anyone knows for sure that this is not possible anyway, please prove and I'll stop testing...). So I used select ...
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232 views

Do OR conditions in Oracle SQL queries spoil index use / cause full table scan?

I have a query on Oracle 11g of the following type, which results in a series of highly inefficient full table scans: select t.Id, t.ObjectId, t...[other Tasks columns] , od1...[ObjectData1 ...
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323 views

Oracle 11g bug ? not returning the record until I triggered index to invisible and then to visible

We are using Oracle 11g, 11.2.0.3. We know a record exists in a table but a select is not returning it for some odd reason. The execution plans the general query, not forcing any index, shows that ...
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0answers
76 views

Oracle: separate column histograms for partitions

I have a partitioned table like MY_TABLE(PART_KEY, DATE_KEY, ...) with a local partitioned index on (PART_KEY, DATE_KEY). When I collect stats on the table, I end up with a HEIGHT BALANCED histogram ...
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0answers
161 views

How to check what stats were used in query

respected DBAs . . . is it possible to tell when statistics were last accessed by a query using T-SQL? I'm trying to ascertain what statistics are involved in a query, I know I can check the visual ...
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High bandwidth on virtual IP

Description of the environment : An apache server (Drupal) connected to mysql server using a virtual IP. The problem : The (outgoing) bandwidth on VIP has exploded (after a new site version ...
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103 views

Replicating Excel's CHIDIST function in Oracle 11g

I'm attempting to replicate the functionality of an Excel workbook in Oracle. One of the formulae on the worksheet uses CHIDIST, which "Returns the one-tailed probability of the chi-squared ...