120dc073c2
This task loads the stats of the tables that are used in a query, from the trace into the optimizer. This feature is also controlled by optimizer_record_context, and is not enabled by default. The stats such as num_of_records present in the table, indexes if present then their names, along with the average number of records_per_key with in each index are loaded from the trace. Additionally, stats from range analysis i.e. ranges, and the corresponding number of records are also loaded from the trace. The trace context which is in JSON format is firstly set into the session variable optimizer_trace_stored_context. Later, when a user issues a query, the contents of optimizer_trace_stored_context variable is parsed and an in memory representation is build using the class Optimizer_Trace_Stored_Context_Extractor. This class is then used by the optimizer to update and save original values of the tables, indexes, and range stats in the methods "set_statistics_for_table()" of sql_statistics.cc, and "check_quick_select()" of opt_range.cc. After the query gets finished, the statistics that were updated in the optimizer are restored back to the saved original values. The entry point for parsing the json structure is in "mysql_execute_command()" of sql_parse.cc, and similarly exit point i.e. to restore the saved stats of the optimizer is at the end of the same method. |
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| .. | ||
| charsets | ||
| CMakeLists.txt | ||
| errmsg-utf8.txt | ||
| insert_translations_into_errmsg.py | ||
| README.md | ||
A quicker way for adding new language translations to the errmsg-utf8.txt file
Summary
To generate a new language translation of MariaDB use the following pull request (PR) as a template for your work:
You will notice as part of your translation work, you will have to add your language translations to the file sql/share/errmsg-utf8.txt which is found in the current directory. This file is long with many sections which can make the translation work tedious. In this README, we explain a procedure and provide a script insert_translations_into_errmsg.py that cuts down the amount of tedium in accomplishing the task.
Procedure
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Start by grepping out all the english translations from errmsg-utf8.txt using the following grep command, and redirecting the output to a file:
grep -P "^\s*eng\s" errmsg-utf8.txt > all_english_text_in_errmsg-utf8.txt
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Next use Google translate to obtain a translation of this file. Google translate provides the ability to upload whole files for translation. For example, this technique was used to obtain Swahili translations which yielded a file with output similar to the below (output is truncated for clarity):
sw "hashchk" sw "isamchk" sw "LA" sw "NDIYO" sw "Haiwezi kuunda faili '% -.200s' (kosa: %iE)" sw "Haiwezi kuunda jedwali %
s.%s (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s' (kosa: %iE)" sw "Haiwezi kuunda hifadhidata '% -.192s'; hifadhidata ipo"
Note that Google translate removes the leading whitespace in the translation file it generates. DO NOT add that leading whitespace back!
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Give the translated file an appropriate name (e.g.
all_swahili_text_in_errmsg-utf8.txt) and store it in the same directory witherrmsg-utf8.txtandall_english_text_in_errmsg-utf8.txt. These 3 files will be used by the script insert_translations_into_errmsg.py. -
Proof check the auto-translations in the file you downloaded from Google translate. Note that Google might omit formatting information that will cause the compilation of MariaDB to fail, so pay attention to these.
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Reintegrate these translations into the errmsg-utf8.txt by running the insert_translations_into_errmsg.py script as follows:
chmod ugo+x insert_translations_into_errmsg.py # Make the script executable if it is not.
./insert_translations_into_errmsg.py <errmsg-utf8.txt file>
For example, for the swahili translation, we ran the following:
./insert_translations_into_errmsg.py errmsg-utf8.txt all_english_text_in_errmsg-utf8.txt all_swahili_text_in_errmsg-utf8.txt
The script uses the
errmsg-utf8.txtfile and the grepped english file to keep track of each new translation. It then creates a file in the same directory aserrmsg-utf8.txtwith the nameerrmsg-utf8-with-new-language.txt. -
Check that the reintegration of the new translations into
errmsg-utf8-with-new-language.txtwent OK, and if it did, renameerrmsg-utf8-with-new-language.txttoerrmsg-utf8.txt:mv errmsg-utf8-with-new-language.txt errmsg-utf8.txt
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In the header of errmsg-utf8.txt make sure to add your language long form to short form mapping. E.g. for Swahili, add:
swahili=sw