# ERROR 1956 ER\_PARAMETER\_CAPACITY\_EXCEEDED: Query cannot be completed because the parameter array capacity of 1048576 was exceeded.

There is no limit on the size of an `IN` list directly, the limit is on the number of parameterized constants in the query. Most `IN` lists are just one parameterized constant.

You are most likely to hit this limit if you mix types in the `IN` clause, for example `IN (1, “test")`, here it will be treated as two parameters, but if you use `IN` clause that contains the same type of parameters it will be treated as one parameter.

For example, if you run:

```sql
SELECT * FROM t WHERE c1 IN (1, 2, 3, 4, 5);
```

and look in the table `INFORMATION_SCHEMA.PLANCACHE` you will notice that the values in the `IN` clause are treated as one single argument as shown below:

`SELECT * FROM t WHERE c1 IN(@);`

The number of `@`s is the number of parameterized constants. It's just one in this case.

You need about one million `@`s to hit this error.

For example consider this query with one million `OR`s:

`SELECT * FROM t WHERE c1 = 1 or OR c1 = 2 OR c1 =3………..;`

maps to:

`SELECT * FROM t WHERE c1 = @ OR c1 = @ OR c1 =@…………;`

A query with multiple subqueries, that contain the `IN` clause can also generate a large number of `@`s. SingleStore will create a new `@` for each row in the `SELECT`. Depending on the number of `@`s generated eventually a query can reach the end of the parameter array capacity.

Solution: 

The query should be refactored to reduce the number of parameterized constants in the query and subqueries.

***

Modified at: April 27, 2023

Source: [/db/v9.1/reference/troubleshooting-reference/query-errors/error-1956-er-parameter-capacity-exceeded-query-cannot-be-completed-because-the-parameter-array-capacity-of-1048576-was-exceeded/](https://docs.singlestore.com/db/v9.1/reference/troubleshooting-reference/query-errors/error-1956-er-parameter-capacity-exceeded-query-cannot-be-completed-because-the-parameter-array-capacity-of-1048576-was-exceeded/)

(An index of the documentation is available at /llms.txt)