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CTEs (Common Table Expressions): Not materialized, because it is used only once. Explicitly creating the CTE as not materialized looks having better p
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posted @ 2024-12-09 08:07
ZhangZhihuiAAA
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Cross join: Cross join is the default for an unqualified join. chr() Grouping: any_value() array_agg() json_agg(), jsonb_agg() bool_and() bool_or() fi
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posted @ 2024-12-08 18:57
ZhangZhihuiAAA
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Inner join is the default join. Outter join has three categories: left join, right join and full join. starts_with() Lateral join: lateral Lateral joi
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posted @ 2024-12-08 10:13
ZhangZhihuiAAA
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Introduction In this article, we are going to see how Index Selectivity works in relational database systems and why the database Optimizer might choo
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posted @ 2024-12-06 10:06
ZhangZhihuiAAA
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ctid What data type should you use for your primary keys? Integers or UUIDs? In 98% of use cases, you should favor integer types. When we are over int
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posted @ 2024-12-05 22:33
ZhangZhihuiAAA
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inet The essential difference between inet and cidr data types is that inet accepts values with nonzero bits to the right of the netmask, whereas cidr
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posted @ 2024-12-04 09:20
ZhangZhihuiAAA
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Fraction is precise, but slow. Floating point is fast, but imprecise. Two floating point: types real (float4) and double precision (float8). Domain is
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posted @ 2024-12-02 18:24
ZhangZhihuiAAA
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zzh@ZZHPC:/zdata/Github/greenlight$ go install honnef.co/go/tools/cmd/staticcheck no required module provides package honnef.co/go/tools/cmd/staticche
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posted @ 2024-11-29 18:49
ZhangZhihuiAAA
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Makefile: ## help: print this help message help: @echo 'Usage:' @sed -n 's/^##//p' ${MAKEFILE_LIST} | column -t -s ':' | sed -e 's/^/ /' confirm: @ech
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posted @ 2024-11-29 17:58
ZhangZhihuiAAA
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$ make migration name=create_example_table run: go run ./cmd/api psql: psql ${GREENLIGHT_DB_DSN} migration: @echo 'Creating migration files for ${name
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posted @ 2024-11-29 17:02
ZhangZhihuiAAA
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