3.1 编写基本的查询函数 CREATE OR REPLACE FUNCTION search_articles(search_query TEXT) RETURNS TABLE(id INT, title TEXT, content TEXT) AS $$ BEGIN RETURN QUERY SELECT id, title, content FROM articles WHERE to_tsvector('english_custom', content) @@ plainto_tsquery('english_custom', search_quer...
create or replace function match_chunks(chunck_embedding vector(1536), threshold float, count int, min_length int) returns table (id bigint, content text, similarity float) language plpgsql as $$ begin return query select doc_chunks.id, doc_chunks.content, (doc_chunks.embedding <#> chunck_e...
例子1,禁止postgres用户在数据库digoal中执行CREATE TABLE和DROP TABLE命令. 创建触发器函数 : CREATE OR REPLACE FUNCTION abort() RETURNS event_trigger LANGUAGE plpgsql AS $$ BEGIN if current_user = 'postgres' then RAISE EXCEPTION 'event:%, command:%', tg_event, tg_tag; end if; END; $$; ...
info text, crt_time timestamp); CREATE TABLE postgres=# insert into t_ret values (1,’digoal’,now()), (2,’DIGOAL’,now()), (3,’digoal’,now()), (4,’abc’,now()); INSERT 0 4 postgres=# create or replace function tg_t_ret() returns trigger as ...
Returnssum(y^2)-sum(y)^2/N(“sum of squares” of the dependent variable) as afloat, orNoneif there aren’t any matching rows. Usage examples¶ We will use this example table: |FIELD1|FIELD2|FIELD3||---|---|---||foo|1|13||bar|2|(null)||test|3|13| Here’s some example...
\c postgres mydbuser postgres=$ create table mytable (id int); postgres=# create user mydbuser; postgres=# \c postgres mydbuser postgres=$ create table mytable (id int); the following example works in postgresql 15 and later: copy to ...
-- an example function which updates a hypothetical -- event_responses table which itself is distributed by event_id CREATE OR REPLACE FUNCTION register_for_event(p_event_id int, p_user_id int) RETURNS void LANGUAGE plpgsql AS $fn$ BEGIN INSERT INTO event_responses VALUES ($1, $2, 'yes...
create_distributed_table https://docs.citusdata.com/en/v10.2/develop/api_udf.html#create-distributed-table UDF 使用分片计数的默认配置值。我们建议在集群中使用 2-4 倍于CPU 核的分片。使用这么多分片可以让您在添加新的工作节点后重新平衡集群中的数据。 2-4 倍于CPU 核的分片 https://docs.citusdata...
Fixed an issue with handling of column name alias which may cause client to hang if column name alias contains string of length more than 64 bytes, for example, select col as '您对“数据一览“中的车型,颜色,内饰,选装, '. Fixed datatype of information_schema_tsql.tables.TABLE_TYPE column....
In the tutorial we will use examples to show what SQL statements returns from the database: Example Sort the table by year: SELECT * FROM cars ORDER BY year; Run Example » Learning by Exercises Many chapters in this tutorial end with an exercise where you can check your level of knowle...