m

db/sql/postgres/feature/functions/gen-data.txt

@@ -1,3 +1,3 @@
 https://www.postgresql.org/docs/current/functions-srf.html
     https://postgrespro.ru/docs/postgrespro/17/functions-srf
-... from generate_series(1, 10000) as id;
+... from generate_series(1, 1e6) as id;

db/sql/postgres/feature/internals/storage/storage.txt

@@ -1,3 +1,6 @@
+https://www.postgresql.org/docs/current/storage.html
+https://www.postgresql.org/docs/current/storage-page-layout.html
+
 each table consists from multiple layers
 each file is no more than 1 Gb
 

db/sql/postgres/feature/internals/vacuum/vacuum-cfg.txt

@@ -0,0 +1 @@
+https://www.postgresql.org/docs/current/runtime-config-autovacuum.html

db/sql/postgres/feature/performance/docs/courses.txt

@@ -1,10 +1,10 @@
 2023
+Tenzor - Borovikov - Backend School for PG
+    https://www.youtube.com/playlist?list=PLt0vzWoDuwcTdFnp-QWtx2yEvKMDlPw7l
+    https://github.com/Kilor/PG-for-beginners
 PostgresProfessional - RogovLuzanovTolmachyov - QPT13 - Query Optimization of p12
     https://postgrespro.ru/education/courses/QPT
     https://www.youtube.com/playlist?list=PLaFqU3KCWw6JW80WBHPOe-SMJD2NOjmge
 2019
 PostgresProfessional - RogovLuzanovTolmachyov - QPT10
     https://www.youtube.com/playlist?list=PLaFqU3KCWw6K2sTAksX5AJq4SQDN5PA1t
-????
-Tenzor - Borovikov
-    https://github.com/Kilor/PG-for-beginners

db/sql/postgres/feature/performance/explain/presentations.txt

@@ -1,5 +1,25 @@
 2023
 Tenzor - Backend School p4 - Query Analysis p2 0:00 of 1:40:59
     https://www.youtube.com/watch?v=Rg7AAEso3z0
-Tenzor - Backend School p4 - Query Analysis p1 0:00 of 1:24:11
+Tenzor - Backend School p4 - Query Analysis p1 9:00 of 1:24:11
     https://www.youtube.com/watch?v=4g2CJv0jRk0
+    ! 3:00  - by default PG does not get hints regarding plans
+    ! 18:00 - explain(settings) select * from pg_class; -- to check current settings
+    !         https://www.postgresql.org/docs/current/runtime-config.html
+    ! 27:48 - if counts of planned and actual record does not near the same, most probably statistics is obsolete
+    !         https://www.postgresql.org/docs/current/planner-stats.html
+    !         https://www.postgresql.org/docs/current/runtime-config-autovacuum.html
+    ! 30:32 !!! not enough statistics
+    !         alter table ... alter column ... set statistics [0..10000] -- columns of hystogram (max 10000 per column)
+    !         https://www.postgresql.org/docs/current/sql-createstatistics.html
+    ! 39:00 - shared_buffers setting need to be increased if multiple clients get mostly the same data
+    ! 43:00 - set io_track_timings=on; explain analyze ...
+    ! 52:00 - ! rows removed by filter should be small
+    ! 58.00 - https://www.postgresql.org/docs/current/storage.html
+    ! 59.00 - https://www.postgresql.org/docs/current/storage-page-layout.html
+    !         TID Scan - the dumbiest one
+    !         Seq Scan - linear, dumb one
+    !         Index Scan - smart
+    !         Index Only Scan - smartest
+    ! 1:09:00 - if Heap Fetches quite large, we made worse by this idx, compare to just "Index Scan"
+    ! 1:13:00 - Foreign Scan - for tables on ext servers

db/sql/postgres/feature/performance/index/presentations.txt

@@ -21,10 +21,62 @@ JPoint - Sitnikov - B-Tree indices using Boot, PostgreSQL, JPA 18:00 of 45:07
     !   select ... from users where state = 'PENDING' and name = ?
     !       create index state_name_users on users(name) include(state)  -- idx will not sort by state, just include it
     !   create index of (col1, col2) -- index sorted on combination of state, name
-Tenzor - Backend School - PG Indices p2 0:00 of 1:21:33
+Tenzor - Backend School - PG Indices p2 2:00 of 1:21:33
     https://www.youtube.com/watch?v=WTELBpLUb2E
-Tenzor - Backend School - PG Indices p1 0:00 of 1:10:44
+    ! 4:00  - hash idx - https://www.postgresql.org/docs/current/hash-index.html
+    ! 6:00  - !! hash idx can be created only on one field (with = operator), we can use op with single eq-op
+    ! 7:00  - create index ... using hash(fild-name);
+    ! 10:00 - gist - generalized search tree -- https://www.postgresql.org/docs/current/gist.html
+    !         universal infrastructure (b-tree, r-tree, rd-tree)
+    ! 12:00 - gist support geom-operators (<<, &<, &>, >>, <@, ~=, &&, <<|, &<|, ~, @), point, box, circle, poly types
+    !         https://www.postgresql.org/docs/current/functions-geometry.html
+    ! 18:00   https://www.postgresql.org/docs/current/functions-net.html, inet-type
+    ! 25:00 - gist is good for ranges ... using gist(daterange(dtb, dte, '[]'));
+    !             ... where daterange(dtb, dte, '[]') @> '2023-01-01'::date; -- 8-times less hits than b-tree
+    ! 29:00 - gist-operators with btree behavior
+    !         https://www.postgresql.org/docs/current/btree-gist.html
+    ! 31:00 - pg-antipatterns for gist - https://habr.com/ru/companies/tensor/articles/679834/
+    ! 40:00 - https://www.postgresql.org/docs/16/gist-examples.html (? no from v17)
+    ! 51:00 - create index ...with (buffering=auto); -- https://www.postgresql.org/docs/16/gist-implementation.html (? no for 17)
+    ! 52:00 - spgist (gist optimized for space partitioning) -- https://www.postgresql.org/docs/current/spgist.html
+    !         only for the single field
+    ! 54:00 - gin (generalized inverted index) -- https://www.postgresql.org/docs/current/gin.html
+    !         https://www.postgresql.org/docs/16/gin-examples.html (? no from v17)
+    ! 1:02:00 - brin - store only min/max or bloom-mask -- https://www.postgresql.org/docs/current/brin.html
+    !           good for cases like append-only logs with timestamps
+    !           https://www.postgresql.org/docs/16/brin-intro.html (? no from v17)
+    ! 1:10:00 - bloom - store only min/max or bloom-mask -- https://www.postgresql.org/docs/current/bloom.html
+    !           logic is the same as for hash
+
+
+Tenzor - Backend School - PG Indices p1 of 1:10:44
     https://www.youtube.com/watch?v=sNCKlklvGO0
+    ! 11:00 - select relname, relpages from pg_class where relaname like 'idx_%';   -- for estimating idx size
+    ! 12:00   create index on <tbl>((field=val))  -- expr-base idx, but bad
+    ! 12:30   create index on <tbl>(field) where field=val;  -- partial/conditional ind - better because size of it is smaller
+    ! 15:00       pg has 3 types of expr: immutable, stable, volatile -- https://www.postgresql.org/docs/current/xfunc-volatility.html
+    !             only immutable are for idx
+    ! 21:00   create index concurrently - for helping queries not to wait, but concurrent-idxes can't be rolled back from transactions
+    ! 24:00 - create unique index ... alter table ... add primary key using index ...
+    ! 25:00 - select * from pg_stat_progress_create_index; -- https://www.postgresql.org/docs/current/progress-reporting.html
+    ! 27:00 - Uber - from PG to MySQL and back - https://habr.com/ru/companies/slurm/articles/322624/
+    ! 28:00 - select * from pg_stat_user_indexes where idx_scan = 0; -- find not-used indexes
+    !         drop index concurrently;
+    ! 31:00 - index types - https://www.postgresql.org/docs/current/indexes-types.html
+    !         btree, hash, gist, spgist, gin, brin, xindex (https://www.postgresql.org/docs/current/xindex.html)
+    ! 33:00   btree - balanced tree, good for ordered types - https://www.postgresql.org/docs/current/btree.html 
+    ! 36:00   btree uses prefix condition idx(a, b, c) - can be used for (a), (a, b)
+    ! 39:00   for conditions a <> .., a not in ... a <> any/all - index will be used very bad (search all the layer)
+    ! 44:00   for btree it is good to use field in cardinality grow order
+    ! 49:00   for btree array field using is bad
+    ! 51:00   ... null values - better to use conditional indexes - where a is not null or b is not null, where (a, b) is not null
+    ! 54:00   if we have 2 independent indexes for (a) and for (b), then select ... where a=1 and b=1; 
+    !         will use use bitmap index scan, but with a lot of rows each
+    !         create idx on (a, b), create idx on (a) where v = 1; create idx on (?) where a=1 and b=1;
+    ! 58:00   suspicious Limit/Sort/Scan
+    !         better to put sorb-by field to index fields tail
+    ! 59:00   btree can be used for prefix like-search ... relname like 'pg\_class\_%'
+    ! 1:05:00 - create index on prefix(md5 text_pattern_ops)    -- use uperator-class text_pattern_ops
 2022
 Percona - A Deep Dive Into PostgreSQL Indexing - Ibrar Ahmad 0:00 of 46:10
     https://www.youtube.com/watch?v=7OvrBmxW_e8

db/sql/postgres/feature/performance/planner/statistics.txt

@@ -1,3 +1,6 @@
+https://www.postgresql.org/docs/current/sql-createstatistics.html
+    !!! alter table ... alter column ... set statistics [0..10000] -- columns of hystogram (max 10000 per column)
+
 https://www.postgresql.org/docs/current/planner-stats.html
 https://www.postgresql.org/docs/current/multivariate-statistics-examples.html
 

pl/java/libfws/mapping/mapstruct.txt

@@ -1,50 +0,0 @@
-http://mapstruct.org/
-
-spring extensions
-https://mapstruct.org/documentation/spring-extensions/reference/html/
-https://github.com/mapstruct/mapstruct-spring-extensions
-
-https://github.com/mapstruct/mapstruct
-https://github.com/mapstruct/mapstruct-examples
-
-http://mapstruct.org/documentation/
-http://mapstruct.org/documentation/installation/
-
-http://mapstruct.org/documentation/reference-guide/
-http://mapstruct.org/documentation/stable/reference/html/
-
-lombok-int
-'org.projectlombok:lombok-mapstruct-binding:0.2.0'
-<scope>provided</scope>
-    If you are using Lombok 1.18.16 or newer you also need to add lombok-mapstruct-binding in order to make Lombok and MapStruct work together.
-https://www.baeldung.com/java-mapstruct-lombok
-
-idea-plugin
-https://plugins.jetbrains.com/plugin/10036-mapstruct-support
-https://github.com/mapstruct/mapstruct-idea
-
-baeldung
-https://www.baeldung.com/tag/mapstruct
-https://www.baeldung.com/mapstruct
-2024
-https://habr.com/ru/articles/818489/
-    https://github.com/yayauheny/javanotice-mapstruct
-2022
-https://reflectoring.io/java-mapping-with-mapstruct/
-    https://github.com/thombergs/code-examples/tree/master/mapstruct
-    ! @MappingTarget - for updating existing instances
-    !!! Exceptions throwing during mapping
-    ! using Formatters
-    ! mapping collections, streams, enums
-    ! default values/expressions and constraints
-    ! @DecoratedWith, @BeforeMapping, @AfterMapping
-    ! additional cfg-options
-2020
-Lviv JavaClub - [Event 159] - MapStruct 0:00 of 1:05:32
-    https://www.youtube.com/watch?v=0fNKc0daZ-c
-2018
-https://habr.com/post/433270/
-
-src
-https://mapstruct.org/documentation/stable/api/org/mapstruct/Mapping.html
-    https://github.com/mapstruct/mapstruct/blob/main/core/src/main/java/org/mapstruct/Mapping.java

pl/java/libfws/mapping/mapstruct/articles.txt

@@ -0,0 +1,21 @@
+baeldung
+https://www.baeldung.com/tag/mapstruct
+https://www.baeldung.com/mapstruct
+2024
+https://habr.com/ru/articles/818489/
+    https://github.com/yayauheny/javanotice-mapstruct
+2022
+https://reflectoring.io/java-mapping-with-mapstruct/
+    https://github.com/thombergs/code-examples/tree/master/mapstruct
+    ! @MappingTarget - for updating existing instances
+    !!! Exceptions throwing during mapping
+    ! using Formatters
+    ! mapping collections, streams, enums
+    ! default values/expressions and constraints
+    ! @DecoratedWith, @BeforeMapping, @AfterMapping
+    ! additional cfg-options
+2020
+Lviv JavaClub - [Event 159] - MapStruct 0:00 of 1:05:32
+    https://www.youtube.com/watch?v=0fNKc0daZ-c
+2018
+https://habr.com/post/433270/

pl/java/libfws/mapping/mapstruct/features/enum-mapping.txt

@@ -0,0 +1,6 @@
+2022
+https://reflectoring.io/java-mapping-with-mapstruct/#mapping-enums
+    @ValueMappings/@ValueMapping
+    <AnyRamaining>/<AnyUnmapped>
+    @EnumMapping(nameTransformationStrategy="...")
+    strategies: suffix, stripSuffix, prefix, stripPrefix

pl/java/libfws/mapping/mapstruct/mapstruct.txt

@@ -0,0 +1,24 @@
+http://mapstruct.org/
+
+spring extensions
+https://mapstruct.org/documentation/spring-extensions/reference/html/
+https://github.com/mapstruct/mapstruct-spring-extensions
+
+https://github.com/mapstruct/mapstruct
+https://github.com/mapstruct/mapstruct-examples
+
+http://mapstruct.org/documentation/
+http://mapstruct.org/documentation/installation/
+
+http://mapstruct.org/documentation/reference-guide/
+http://mapstruct.org/documentation/stable/reference/html/
+
+lombok-int
+'org.projectlombok:lombok-mapstruct-binding:0.2.0'
+<scope>provided</scope>
+    If you are using Lombok 1.18.16 or newer you also need to add lombok-mapstruct-binding in order to make Lombok and MapStruct work together.
+https://www.baeldung.com/java-mapstruct-lombok
+
+idea-plugin
+https://plugins.jetbrains.com/plugin/10036-mapstruct-support
+https://github.com/mapstruct/mapstruct-idea

pl/java/libfws/mapping/mapstruct/src.txt

@@ -0,0 +1,2 @@
+https://mapstruct.org/documentation/stable/api/org/mapstruct/Mapping.html
+    https://github.com/mapstruct/mapstruct/blob/main/core/src/main/java/org/mapstruct/Mapping.java

science/ai/free/deepsek.txt

@@ -3,5 +3,7 @@ https://github.com/deepseek-ai
 https://api-docs.deepseek.com/quick_start/pricing
 
 2025
+Aiii - DeepSeq v3 + make 0:00 of 23:40
+    https://www.youtube.com/watch?v=9Xb6KpVl9dQ
 Makarov - DeepSeq v3 now free 0:00 of 6:29
     https://www.youtube.com/watch?v=cNXTGOy6FQQ