V1元数据存储

[LLiuJJ]

示例表

[1] CREATE DATABASE classdb;

 PUT		 mdatabase_classdb  -> “”;

[2] SHOW DATABASES;

 ITER      database_*

[3] USE classdb;

 MEMOP

[4] CREATE TABLE

CREATE TABLE classtab 
( 
Name VARCHAR(100), 
Class VARCHAR(100), 
Score INT, 
PRIMARY KEY(Name)
);

1.PUT meta_db table_classdb_classtab ->  “name^13$$class^13$$score^7”
select * from classtab where title = ‘c’; // ERROR
2.OPEN data_classdb_classtab pmemkv db instance

[5] DROP DATABASE classdb;

remove meta_db database_classdb -> “”;
remove all table in classdb

[6] DROP TABLE table_name ;

1.remove meta_db table_classdb_classtab -> “###...”
2.delete data_classdb_classtab

[7] INSERT INTO

INSERT INTO classtab 
(
Name, 
Class,
Score
) 
VALUES 
('Tom', 
'B', 
'98');
PUT p_Tom -> Tom$$A$$98 to data_classdb_classtab 

[8]SELECT ;

SELECT * from classtab WHERE Name = 'Tom'

GET p_Tom 
Tom$$A$$98

[9]SELECT * from classdb WHERE score > '100' and score < '120';

慢查询
scan all data_db_table_classdb_classtab
满足条件的捞出

快查询
index_db_table_classdb_classtab
idx_classdb_score_88 -> Tom$$A$$98
idx_classdb_score_98 -> Jary$$B$$88

[10] UPDATE classdb

UPDATE classtab  SET Score='78' WHERE Name='Tom';
GET p_Tom
修改后
PUT p_Tom -> Tom$$A$$78  to db 

[11]DELETE

DELETE FROM classdb WHERE Name='Tom';
data_db_table_classdb_classtab
remove p_Tom

[12] DELETE RANGE

DELETE FROM classdb WHERE score < '99';
scan all, delete 符合条件的

[13] LIKE SELECT

SELECT * from classtab  WHERE Name LIKE '%COM%';
scan all 正则匹配

[14] ORDER BY

SELECT * from classtab ORDER BY submission_date ASC;
scan all data, sort in memory return
submission_date idx

[15] AVG

SELECT AVG(score) AS AverageScore FROM classtab;
scan row data, count score AVG

[16] SUM

SELECT SUM(score) AS TotalScore FROM classtab;
scan all row data, count score SUM