
PostgreSQL: Backend Flowchart - octosphere
https://www.postgresql.org/developer/backend/
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barbecue_sauce
If you're looking for something with similar information to consume passively,
check out Bruce Momjian's fairly detailed talk on Postgres internals:

[https://www.youtube.com/watch?v=JFh22atXTRQ](https://www.youtube.com/watch?v=JFh22atXTRQ)

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etaioinshrdlu
My god, the table join optimizer can use a genetic algorithm. Fascinating. I
would not have thought an SQL database would have a need for such an
algorithm!

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jdnier
[https://wiki.postgresql.org/wiki/Backend_flowchart#optimizer...](https://wiki.postgresql.org/wiki/Backend_flowchart#optimizer_geqo)

 _Genetic query optimizer optimizer /path evaluates all possible ways to join
the requested tables. When the number of tables becomes great, the number of
tests made becomes great too. The Genetic Query Optimizer considers each table
separately, then figures the most optimal order to perform the join. For a few
tables, this method takes longer, but for a large number of tables, it is
faster. There is an option to control when this feature is used._

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whoisthemachine
I haven't seen a map tag in ages, and this seems like a proper use of it!

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derefr
Given that the image here looks like it was generated from a .dot file,
though, it could have just-as-well been exported as an .svg, where the SVG
flowchart-box nodes themselves would have the fragment links attached to them.

As it is, given the comment on how to hand-calculate new <area> coordinates
embedded near the <map> on the page, I think they just used Graphvis to output
a .gif rendering of the flowchart, and then went in and hand-wrote a separate
HTML <map> on top of it. Quite a bit more work, and work that would have to be
duplicated if you ever wanted to tweak and re-export the graph itself.

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deepsun
Wow, that image GIF is such 90-ish design -- bright colors, awful unreadable
fonts...

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jjeaff
The vinn diagram of "people who understand PostgreSQL internals" and "people
who are good at design" probably has a very small overlapped area.

