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How to select specific rows if a column exists or all rows if a column doesn't

mysql

Matt S Matt S

5 My first thought would be to use the `INFORMATION_SCHEMA` first, so you get to know (in one query for all tables in the MySQL instance) which tables have an `active` column and then use that info to construct your queries. And this is probably the most sane approach.

ypercubeᵀᴹ

Get the table start date and end date find the week date

mysql

ramesh ramesh

How to retrieve a large text from inside a table?

sql-server-2016

Marcello Miorelli Marcello Miorelli

5 There's another way similar to Aaron's, using the little-documented `processing-instruction`... thing.

meme

2 You can't copy from text output, because it truncates the data.

aaron bertrand

Howto avoid textdata of trace gets truncated?

sql-server-2008-r2

Magier Magier

3 SSMS always truncates long strings unless typed as XML in which case you can set it to allow unlimited.

Martin Smith

Why is SQL doing an index scan and seek with the same XML query structure?

sql-server

Middletone Middletone

9 XML index in SQL Server is implemented as an internal table that is a persisted version of the node table that is much the same as the XML shredding functions produce.

Mikael Eriksson

7 Consider storing your xml in a more usual format if you can. This might require a change at an earlier stage of the process, or some pre-processing when you import the data, but it could well be worth it.

Paul White

DB Fiddle failes Firebird query 3

Meta

dbfiddle firebird

Arioch Arioch

How to model an entity type that can have different sets of attributes?

mysql

user5613506 user5613506

8 According to your description of the business environment under consideration, there exists a *supertype-subtype* structure that encompasses *Item* —the supertype— and each of its *Categories*, i.e., *Car*, *Boat* and *Plane* (along with two more that were not made known) —the subtypes—.

MDCCL

Is it a bad practice to have several mutually exclusive one-to-one relationships?

Arthur Tarasov Arthur Tarasov

4 The different types of cars are an instance of a general problem that surfaces over and over again in data modeling. It is called "generalization/specialization" in ER modeling, and "superclass/subclass" in object modeling.

Walter Mitty

3 There is nothing wrong with having as many entity sub-types in your model as are needed to reflect the reality of the data that you're trying to model. The question isn't whether sub-types are a bad practice. The issue _may_ be is it a **good model**?

Joel Brown

Upgrading Postgres 12 to 13: pg_upgrade.exe fails 17

postgresql

Marc.2377 Marc.2377

6 The answer had to do with the option "*Beta: Use Unicode UTF-8 for worldwide language support*" being checked in my locale settings in Windows.

Marc.2377

Hide Schema and DDL for testing purposes

Anonymous 1869 Anonymous 1869

@PeterVandivier [SQL Server 2019 on Ubuntu 20.04, python2 dependency removed for SQL Server 2019 across distributions.](https://techcommunity.microsoft.com/t5/sql-server/sql-server-2019-on-ubuntu-20-04-python2-dependency-removed-for/ba-p/2259118)

::: quote 2 87687 6da41129661867ded98757f884fbbd8151b27a31e604efc79bce2d85a6953da5 212,223,236 62,103,153 PeterVandivier[ *— 2 months ago*](#c87687) >> The [following commands](https://docs.microsoft.com/en-us/sql/linux/quickstart-install-connect-red-hat) for SQL Server 2019 points to the RHEL 8 repository. RHEL 8 does not come preinstalled with python2, which is required by SQL Server. Before you begin the SQL Server install steps, execute the command and verify that python2 is selected as the interpreter > >🤮 :::

It's about half way down the page, this is what you should be able to see: > timeElapsed The elapsed time for the job. This is the difference between the start datetime and the end datetime or the datetime of the current sample, if the job does not yet have an end datetime. Depending on the actual time elapsed, this field will be displayed in the format \<dddd:hh:mm:ss>.

Found it mentioned [here](https://docs.itrsgroup.com/docs/geneos/5.0.0/Netprobe/ibmi/index.html). I'm guessing this is a time interval format rather than a date/time format. Of course that means that it shouldn't have a time zone indicator, and since your example does have one, then maybe the format has other uses (or someone thinks it does).

anyone recognise this timestamp format? `0031:02:06:11.01 EST` got asked what it might be in work chat and i'm at a loss. thought it might be leading DayOfYear or something but that doesn't quite make sense

it's a lot if that 1/10th is accessed much more frequently than the other 80% — but the target advice is only an estimate. You can bump it up by a smaller amount and see what gain you get, then rinse/repeat until you've got all the low hanging fruit.

SQL> show parameters pga; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ pga_aggregate_limit big integer 22272M pga_aggregate_target big integer 11136M SQL>`