sql query analyzer 2017

Use pt-query-digest to find the SQL statement that is not suitable, pt-query-digestsql Overview of pt-query-digest1. Indexes can be executed more quickly, but there must be unreasonable indexes. If you want to find those indexes that are not very suitable and optimize them before they become problems, you can use the p

can help us solve the problem. The sample name is variables. ktr. Do not forget to assign a value to parameter during the runtime for testing. Use variables and placeholders together If necessary, we can mix these two technologies. In this example, variables are used as table nouns and Placeholders are used as input values for the previous step. The sample file variables_and_placeholders.ktr. SELECT name, population FROM $ {ANIMALS_TABLE} WHERE population>? Sample download You canHereDownload

To analyze the performance of a query, you can view {Tagshow (event, '% D6 % B4 % D0 % D0 % BC % C6 % BB % AE ');} "Href =" javascript:; "target =" _ Self ">Execution Plan. Execution Plan description {Tagshow (event, 'SQL ');} "Href =" javascript:; "target =" _ Self ">SQL{Tagshow (event, 'server ');} "Href =" javascript:; "target =" _ Self ">ServerHow the

SQLServer how to use the T-SQL command to query a database in which tables, convenient table operations, need friends can refer to the next SQLServer how to use the T-SQL command to query a database in which tables, convenient table operations, need friends can refer to the next 1.

char (65 ); Select nchar (65 ); Select nchar (45231 ); Select nchar (32993); -- unicode conversion character Select unicode ('A'), unicode ('中'); -- returns the unicode encoding value. Select soundex ('hello'), soundex ('World'), soundex ('word '); Select patindex ('% A', 'ta'), patindex ('% ac %', 'jack'), patindex ('dex % ', 'dexjack '); -- match Character index Select 'A' + space (2) + 'B', 'C' + space (5) + 'D'; -- output space Select charIndex ('O', 'Hello World'); --

1. Query all tables in sql: Select table_name from database name. Information_schema. Tables Where table_type= ' BASE table ' is executed, you can see the names of all the tables in the database that belong to you 2. Query all tables and columns in sql:Select Dbo.sysobjects.name as TABLE_NAME, dbo.syscolumns.name as column_name from Dbo.syscolumns INNER JOIN

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order. 2. Try to avoid null value determination on the field in the where clause. Otherwise, th

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order.2. Try to avoid null value determination on the field in the where clause. Otherwise, the

=half_million.counter);QUERY PLAN______________________________________________________________Merge Join (cost=4.12..37650.65 rows=500000 width=42)(actual time=0.033..3272.940 rows=500000 loops=1)Merge Cond: (one_million.counter = half_million.counter) -> Index Scan using one_million_counter_idx on one_million (cost=0.00..32129.34 rows=1000000 width=37) (actual time=0.011..694.466 rows=500001 loops=1) -> Index Scan using half_million_coun

. cid = c. id;6. Self-join (query connections for the same table)-- Self-connectionSelect distinct s. * from student s, student s1 where s. id Ø Functions1. Aggregate functionsMax maximum, min minimum, count statistics, avg average, sum, var varianceSelectMax (age) max_age,Min (age) min_age,Count (age) count_age,Avg (age) avg_age,Sum (age) sum_age,Var (age) var_ageFrom student;2. Date and Time FunctionsSelect dateAdd (day, 3, getDate (); -- add daySel