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How big is too big for a PostgreSQL table?
...u are doing.
Depending on your data distribution you can use a mixture of indexes, filtered indexes, and table partitioning of some kind to speed thing up once you see what performance issues you may or may not have. Your problem will be the same on any other RDMS that I know of. If you only need ...
What's the fastest way to merge/join data.frames in R?
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In the sqldf code that was posted in the question, it might appear that indexes were used on the two tables but, in fact, they are placed on tables which were overwritten before the sql select ever runs and that, in part, accounts for why its so slow. The idea of sqldf is that the data frames in...
How to change identity column values programmatically?
...oning, apparently). Note that the table has to match pretty-much exactly (indexes, FKs, etc)
– Mark Sowul
Sep 9 '14 at 14:22
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How to undo “git commit --amend” done instead of “git commit”
... Move the current head so that it's pointing at the old commit
# Leave the index intact for redoing the commit.
# HEAD@{1} gives you "the commit that HEAD pointed at before
# it was moved to where it currently points at". Note that this is
# different from HEAD~1, which gives you "the commit that i...
SVN encrypted password store
I installed SVN on a Ubuntu machine and I can't get my head around something.
3 Answers
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size_t vs. uintptr_t
The C standard guarantees that size_t is a type that can hold any array index. This means that, logically, size_t should be able to hold any pointer type. I've read on some sites that I found on the Googles that this is legal and/or should always work:
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How can I use optional parameters in a T-SQL stored procedure?
...fference, can have massive performance implications. The key is to use an index, ignore compact code, ignore worrying about repeating code, you must make a good query execution plan (use an index).
Read this and consider all the methods. Your best method will depend on your parameters, your data,...
What is the minimum valid JSON?
... or a JSONArray as specified by RFC 4627.
snipped
This would mean that all JSON values (including strings, nulls and numbers) are accepted by the JSON object, even though the JSON object technically adheres to RFC 4627.
Note that you could therefore stringify a number in a conformant browser via...
What is the difference between Scope_Identity(), Identity(), @@Identity, and Ident_Current()?
...know Scope_Identity() , Identity() , @@Identity , and Ident_Current() all get the value of the identity column, but I would love to know the difference.
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What is PAGEIOLATCH_SH wait type in SQL Server?
...o large scans over big tables. It almost never happens in queries that use indexes efficiently.
If your query is like this:
Select * from <table> where <col1> = <value> order by <PrimaryKey>
, check that you have a composite index on (col1, col_primary_key).
If you don't hav...