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How to design a database for User Defined Fields?
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If performance is the primary concern, I would go with #6... a table per UDF (really, this is a variant of #2). This answer is specifically tailored to this situation and the description of the data distribution and access patterns described.
Pros:
Because you indicate that some UDFs
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Find all tables containing column with specified name - MS SQL Server
Is it possible to query for table names which contain columns being
29 Answers
29
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How do I import CSV file into a MySQL table?
...alized events-diary CSV from a client that I'm trying to load into a MySQL table so that I can refactor into a sane format. I created a table called 'CSVImport' that has one field for every column of the CSV file. The CSV contains 99 columns , so this was a hard enough task in itself:
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Alternate table row color using CSS?
I am using a table with alternate row color with this.
9 Answers
9
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In MySQL what does “Overhead” mean, what is bad about it, and how to fix it?
...uld only worry if this gets really high.
You can compare 'Optimizing the table' with the defragmenting of your hard drive.
I quote:
Every database will, over time,
require some form of maintenance to
keep it at an optimal performance
level. Purging deleted rows,
resequencing, compre...
SQL “select where not in subquery” returns no results
... query:
LEFT JOIN / IS NULL:
SELECT *
FROM common
LEFT JOIN
table1 t1
ON t1.common_id = common.common_id
WHERE t1.common_id IS NULL
NOT EXISTS:
SELECT *
FROM common
WHERE NOT EXISTS
(
SELECT NULL
FROM table1 t1
WHERE t1.common_id = ...
Why were pandas merges in python faster than data.table merges in R in 2012?
...ark performs very fast in-memory merges. It's even faster than the data.table package in R (my language of choice for analysis).
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Create a table without a header in Markdown
Is it possible to create a table without a header in Markdown?
11 Answers
11
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WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT
...re the constraint is enabled even if the default constraint behavior for a table is changed.
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What does .SD stand for in data.table in R
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.SD stands for something like "Subset of Data.table". There's no significance to the initial ".", except that it makes it even more unlikely that there will be a clash with a user-defined column name.
If this is your data.table:
DT = data.table(x=rep(c("a","b","c"),eac...