What's the equivalent of blackhole?

I'm starting a new project in postgreSQL (lastest) having worked with MySQL 5.5 for a while.

In the past I've made heavy use of blackhole table to simplify my application code.
It allows me to do one insert in application code:

INSERT INTO blackhole1 (val1, val2, val3, val4 ...

CREATE TRIGGER ai_blackhole1_each AFTER INSERT ....
BEGIN
  INSERT INTO table1 (....
  INSERT INTO table2 (....
  INSERT INTO log (.....

And have a trigger in the blackhole table insert the values into different tables.

What do I use in postgreSQL to replace this functionality?

I know I can use a stored procedure, but that means that I cannot connect data-aware controls to a 
blackhole-table. So I would love the stick as close to the MySQL original as possible.

 Answers

What is a BLACKHOLE?

In MySQL-speak, BLACKHOLE is a storage engine that simply discards all data INSERTed into it, analogous to a null device. There are a number of reasons to use this backend, but they tend to be a bit abstruse:

• A "relay-only" binlog-filtering slave
  See the docs, and here.
• Benchmarking
  E.g., measuring the overhead of binary logging without worrying about storage engine overhead

If you don't know why you need a data sink masquerading as a table, don't use it.

What is the technique you are asking about?

The use under consideration seems to be to:

1. redirect INSERTed data to other tables
2. audit log the original INSERTion action
3. discard the original INSERT data

Thus the answer to the question of "evilness" or pros/cons is the same as the answer to those questions for insertable/updatable VIEWs (the common way to implement #1), trigger-based audit logging (how most people do #2) and behavioral overrides/counteractions generally (there are a number of ways to accomplish #3).

So, what is the answer?

The answer is, of course, "sometimes these techniques are appropriate and sometimes not." :) Do you know why you're doing it? Is the application a better place for this functionality? Is the abstraction too brittle, too leaky, too rigid, etc.?

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inserting in different tables through one mysql query

Short answer

No you can't insert into more than one table using a single SQL statement.

Longer answer

You can achieve it by inserting into table1 and then setting up a trigger on table1 to insert data into tables 2 and 3 using a BLACKHOLE table to store your data transiently. 

Personally I would avoid this like the plague since it obscures how & where data is being inserted into the database from a given application. 

If I were you I would just write three separate INSERT statements in your php application and avoid trying to create a single query that inserts into multiple tables. It'll save you a great deal of pain!

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As far as I know, PHP's mysql_query() function doesn't support multiple queries (insert, select, update etc), and as you are inserting into different tables with different fields/columns, you have to run a separate query for each. I don't think there is a way to do what you want.