Limits & Constraints

Limits & Constraints

Resource limits and constraints across the db9 engine and extensions.

Engine Limits

Resource	Limit
Statement timeout	60s (default)
Idle transaction timeout	600s / 10 min (default)

Statement timeout can be changed per session

The default statement timeout of 60 seconds can be overridden per session with SET statement_timeout = '120s'. Long-running operations like index builds or data migrations may need this adjustment.

| View nesting depth | 64 levels | | Pending portals per connection | 32 | | Timestamp precision | Milliseconds (not microseconds) |

DB9 Difference: Millisecond timestamp precision

DB9 timestamps have millisecond precision, not microsecond like standard PostgreSQL. Fractional-second syntax (e.g., TIMESTAMP(6)) is accepted but values below 1ms are not representable.

| Encoding | UTF-8 only |

HTTP Extension Limits

Resource	Limit
Connect timeout	1s
Total timeout	5s
Max request body	256 KiB
Max response body	1 MiB
Max calls per statement	100
Max concurrent per tenant	20

fs9 Extension Limits

Resource	Limit
Max file size	100 MB
Max glob total size	100 MB
Max file traversal	10,000 files
Max directory recursion	10 levels

pg_cron Limits

Resource	Limit
Job execution timeout	Default: 5 minutes; max: 30 minutes

Unsupported PostgreSQL Features

The following PostgreSQL features are not supported:

• SMALLINT / INT2 type — aliased to INTEGER (32-bit)
• REAL / FLOAT4 type — aliased to DOUBLE PRECISION (64-bit)
• CHAR(n) fixed-length type — aliased to VARCHAR(n) (no padding semantics)
• LISTEN / NOTIFY async notifications
• Microsecond timestamp precision (millisecond only)