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Is it save to write to the same sym file by 2 or more q processes currently
Hello,
I have a concern when 2 or more q processes a writing/updating the enumeration in a single sym file by .Q.en[] or ‘:/<sympath>/sym?newsymbols concurrently. Do these operations are multi-process safe? I am a little confused in the documentation:
The file is locked at a process level for writing during .Q.en only. Avoid reading from any file which may be being written to.
The system call used is https://linux.die.net/man/3/lockf.
Does this means that only .Q.en[] is performing the locking?
(Referring to the documentation) ‘:/<sympath>/sym?newsymbols should also uses the file lock, is this correct?
Thank you very much.
Jacky
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2 Replies
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.Q.en uses ?. It is ? that does the locking. So both at the same time is fine.
See:
https://code.kx.com/q/ref/enum-extend/#filepath
code.kx.com
Enum Extend | Reference | kdb+ and q documentation - kdb+ and q documentation
Enum Extend is a q operator that extends an enumeration.
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Thanks so much😀
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