PostgreSQL Query Catalog

Uppercase means screaming and having code entirely in uppercase makes its reading more difficult. On the other hand, it would be a good idea to have keywords in uppercase. Find routines that body contains a SQL data manipulation statement (which shouldn't be entirely in uppercase) but still the body is completely in uppercase.

Use a right predicate in trigger condition in order to ensure that the trigger executes always when it has to but not more often. IS DISTINCT FROM treats NULL as if it was a known value, rather than unknown. It would be relevant if a column that is referenced in the action condition is optional, i.e., permits NULLs.

Use a right predicate in trigger condition in order to ensure that the trigger executes always when it has to but not more often. IS DISTINCT FROM treats NULL as if it was a known value, rather than unknown. It would be relevant if a column that is referenced in the action condition is optional, i.e., permits NULLs.

Use consistent style of naming. Prefer snake_case. Regular identifiers are stored in the PostgreSQL system catalog in lowercase. Thus, if you use, for instance the identifier thisIsLongTableName, then, for instance,in the pg_dump result you will see the table name thisislongtablename. If the name in the system catalog is thisIsLongTableName, then it means that the name is a delimited identifier, i.e., case sensitive.

Use different names to avoid confusion.

Use different names to avoid confusion.

Use parameter names instead of positional references to improve code evolvability.

Users (applications) should ideally use a database through virtual data layer and thus not directly use base tables. If there is a need to provide direct access to the base tables, then one should grant access based on the principle of least privilege, i.e., to the minimum possible number of base tables.

Use SQL language instead of PL/pgSQL where possible. Instead of using an IF statement, you can check as to whether the data modification succeeded or not by using the RETURNING clause in the data modification statement.

Use the same mechanism of generating surrogate key values throughout the database. The use of SERIAL notation/explicitly creating a sequence generator and declaration of a column as an identity column will cause the creation of an external and internal sequence generator, respectively. Nevertheless, one should try to stick with using one of the mechanisms in order to cause less confusion. "If you do something a certain way, do all similar things in the same way." (Robert C. Martin, Clean Code)

Using PL/pgSQL may cause context switching between declarative SQL and procedural PL/pgSQL. Thus use PL/pgSQL only if you truly need some of its constructs (variables, conditional statements, cycles, cursors, exception handling).

Using PL/pgSQL may cause context switching between declarative SQL and procedural PL/pgSQL. Thus use PL/pgSQL only if you truly need some of its constructs. You can create table functions by using SQL.

What are the base tables and foreign tables without any associated (directly or through domains) check constraints? A NOT NULL constraint is a kind of CHECK constraint. However, this query does not take into account NOT NULL constraints.

What are the pairs of base tables that have at least two columns with the same names and data types. The tables might violate the principle of orthogonal design and hence might facilitate uncontrolled data redundancy over different tables.

What is the percentage of optional columns (that permit NULLs) in case of each base table? It is better to prohibit the use of NULLs in as many columns as possible. Otherwise the results of queries may be misleading.

Working with sets of rows rather than processing each row separately is more effective.

Write code that is easy to understand and not unnecessarily long. A routine cannot have two or more parameters with the same name. In this case using longer identifier in the form routine_name.parameter name is unnecessary.

Write code that is simple to understand and not confusing. A double negative is a grammatical construction occurring when two forms of negation are used in the same expression (https://en.wikipedia.org/wiki/Double_negative). Double negatives in Boolean expressions make it more difficult to understand and maintain the code.

Write correct code. If you pass arguments to a trigger function, then the function should use the arguments. TG_ARGV[]: "Data type array of text; the arguments from the CREATE TRIGGER statement. The index counts from 0. Invalid indexes (less than 0 or greater than or equal to tg_nargs) result in a null value." (PostgreSQL documentation)

Write correct code "The return value of a row-level trigger fired AFTER or a statement-level trigger fired BEFORE or AFTER is always ignored; it might as well be null." (PostgreSQL documentation)