Viewing Data

Query information about all tables in a database through the system catalog pg_tables:
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SELECT * FROM pg_tables;
Run the \d+ command of the gsql tool to query table attributes:
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\d+ customer_t1;
Query the data volume of the table customer_t1:
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SELECT count(*) FROM customer_t1;
Query all data in table customer_t1:
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SELECT * FROM customer_t1;

Query data in column c_customer_sk:

     
          SELECT c_customer_sk FROM customer_t1;

Filter repeated data in column c_customer_sk:

     
          SELECT DISTINCT( c_customer_sk ) FROM customer_t1;

Query all data whose column c_customer_sk is 3869:

     
          SELECT * FROM customer_t1 WHERE c_customer_sk = 3869;

Sort data based on column c_customer_sk.
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SELECT * FROM customer_t1 ORDER BY c_customer_sk;
To cancel a query that has been running for a long time, see Viewing and Stopping the Running Query Statements in Querying System Catalogs.