# Inbox table > Every column of the inbox table on PostgreSQL and SQL Server, with its type, nullability, default and writer. This page describes every column of the `inbox` table that the bundled migrations create, on PostgreSQL and on SQL Server. QueueBox writes one row for each accepted message of a source. The application reads the table only through a [pull client](/reference/pull-clients/), or for an operational question. `database.inboxTableName` and `database.columnMapping.inbox` rename the table and its columns. See the [configuration](/reference/configuration/#databasecolumnmappinginbox) page. ## Columns | Column | PostgreSQL type | SQL Server type | Null | Default | Written by | | --- | --- | --- | --- | --- | --- | | `id` | `UUID` | `UNIQUEIDENTIFIER` | no | `gen_random_uuid()` / `NEWID()` | QueueBox, at receipt | | `source` | `VARCHAR(255)` | `NVARCHAR(255)` | no | none | QueueBox, at receipt | | `idempotency_key` | `VARCHAR(255)` | `NVARCHAR(255)` | no | none | QueueBox, at receipt | | `aggregate_id` | `VARCHAR(255)` | `NVARCHAR(255)` | yes | none | QueueBox, at receipt | | `event_type` | `VARCHAR(255)` | `NVARCHAR(255)` | yes | none | QueueBox, at receipt | | `payload` | `JSONB` | `NVARCHAR(MAX)` | no | none | QueueBox, at receipt | | `headers` | `JSONB` | `NVARCHAR(MAX)` | no | `'{}'` | QueueBox, at receipt | | `correlation_id` | `VARCHAR(128)` | `NVARCHAR(128)` | yes | none | QueueBox, at receipt | | `consumption` | `VARCHAR(4)` | `VARCHAR(4)` | no | `'push'` | QueueBox, at receipt | | `state` | `VARCHAR(50)` | `NVARCHAR(50)` | no | `'pending'` | QueueBox, the relay or a pull client | | `created_at` | `TIMESTAMP WITH TIME ZONE` | `DATETIME2` | no | `CURRENT_TIMESTAMP` / `GETUTCDATE()` | The default | | `processed_at` | `TIMESTAMP WITH TIME ZONE` | `DATETIME2` | yes | none | The relay or a pull client | | `scheduled_at` | `TIMESTAMPTZ` | `DATETIME2` | no | `CURRENT_TIMESTAMP` / `SYSUTCDATETIME()` | The default, then a pull client on a retry | | `attempt` | `INT` | `INT` | no | `0` | A pull client on a retry | | `last_error` | `TEXT` | `NVARCHAR(MAX)` | yes | none | A pull client on a retry or a dead letter | | `claimed_at` | `TIMESTAMP WITH TIME ZONE` | `DATETIME2` | yes | none | The relay or a pull client | | `claim_token` | `UUID` | `UNIQUEIDENTIFIER` | yes | none | The relay or a pull client | | `lease_expires_at` | `TIMESTAMPTZ` | `DATETIME2` | yes | none | The relay or a pull client | The pair `(source, idempotency_key)` carries the unique constraint `uq_inbox_source_idempotency`. The constraint is the deduplication. ## Columns set at receipt ### id The row identifier. The relay sends it on the outbox row as the `x-inbox-id` header. ### source The name of the source in `queuebox.yml`, for example `stripe`. It is the key of the `sources` map, not the path of the HTTP route. ### idempotency_key The deduplication key inside one source. A second message with the same source and key is a duplicate, and QueueBox stores no second row. Two sources can hold the same key, because the source is part of the identity. The [headers](/reference/headers/#headers-that-queuebox-reads) page gives the order in which each kind of source finds the key. When a broker source finds no key, it writes `sha256:` and the hexadecimal SHA-256 digest of the body. ### aggregate_id The unit of order of the inbox. It comes from `aggregateIdPath`, or from a header or the record key on a broker source. At most one row of an aggregate is in flight at a time. The relay copies the value into the outbox `key`. [Ordering](/concepts/ordering/) states the rules for push and pull rows. ### event_type The event type from `eventTypePath`, or from the event type header of a broker source. The topic template reads it as `{{ eventType }}`. ### payload The message body as JSON, after the source transform. A broker message whose body is not JSON becomes a dead row with the payload `{"raw": ""}`. ### headers A JSON object of the received headers, one string value per name. A repeated name keeps its last value. | Source kind | Content | | --- | --- | | `http` | The request headers, except `Authorization`, `Proxy-Authorization`, `Cookie` and the header that the source `auth` block reads. | | `rabbitmq` | The AMQP headers. A number, a boolean or a timestamp becomes its string form. A nested table or array becomes JSON text. A byte array becomes UTF-8 text, or `base64:` and its Base64 text when it is not valid UTF-8. | | `kafka` | The record headers as UTF-8 text, or `base64:` and the Base64 text when a value is not valid UTF-8. | | `nats` | The message headers. A name with several values keeps its last value. | QueueBox stops at start when the table has no headers column. The error holds the `ALTER TABLE` statement that adds it. ### correlation_id The identifier that follows the message through every log line. It comes from the `X-Correlation-Id` header, or QueueBox generates a UUID. QueueBox removes control characters and keeps at most 128 characters. ### consumption `push` or `pull`, from the `consumption` key of the source at receipt. A check constraint allows only these two values. A later change of the configuration does not change a stored row. The relay claims push rows only. ## Columns of the claim ### state The position of the row in its life cycle. The meaning of a processed row depends on `consumption`. For a push row, it means that the relay copied the row into the outbox. For a pull row, it means that the application finished its work. [How QueueBox works](/concepts/how-queuebox-works/) lists the states and the transitions between them. ### created_at and processed_at `created_at` is the receipt time. The retention age policy of the inbox measures from it. `processed_at` is the time of completion. The inbox has no `updated_at` column. ### scheduled_at and attempt A pull claim takes a row only when `scheduled_at` has passed. A pull retry moves `scheduled_at` forward and raises `attempt` by one. The relay does not use these two columns. ### last_error The reason that a pull client gives on a retry or a dead letter. The pull clients remove secret values from the text before they write it. ### claimed_at, claim_token and lease_expires_at A claim sets all three: the claim time, a new random token and the end of the lease. Every completion, retry, renewal and dead letter matches the token and a lease that has not passed. An update that matches no row means that the claim was lost. A pull completion, retry or dead letter clears `claim_token` and `lease_expires_at`. [Claims and leases](/concepts/claims-and-leases/) explains the model. ## Indexes | Index | Columns | Filter | | --- | --- | --- | | Primary key | `id` | none | | `uq_inbox_source_idempotency` | `source`, `idempotency_key` | unique | | `idx_inbox_pending` | `state` | pending rows | | `idx_inbox_source` | `source` | none | | `idx_inbox_aggregate_state` | `aggregate_id`, `state` | none | | `idx_inbox_processing_claimed` | `claimed_at` | processing rows | | `idx_inbox_state_created` | `state`, `created_at` | none | | `idx_inbox_consumption_pending` | `consumption`, `state`, `scheduled_at` | none | | `idx_inbox_pull_pending` | `source`, `scheduled_at`, `created_at`, `id` | pending pull rows | | `idx_inbox_pull_busy` | `source`, `aggregate_id`, `lease_expires_at` | processing pull rows | | Index | Columns | Filter | | --- | --- | --- | | Primary key | `id` | none | | `uq_inbox_source_idempotency` | `source`, `idempotency_key` | unique | | `idx_inbox_state` | `state` | none | | `idx_inbox_state_created` | `state`, `created_at` | none | | `idx_inbox_aggregate_state` | `aggregate_id`, `state` | none | | `idx_inbox_processing_claimed` | `claimed_at` | processing rows | | `idx_inbox_consumption_pending` | `consumption`, `state`, `scheduled_at` | none | | `idx_inbox_pull_pending` | `source`, `scheduled_at`, `created_at`, `id` | pending pull rows | | `idx_inbox_pull_busy` | `source`, `aggregate_id`, `lease_expires_at` | processing pull rows | ## Example query Read the table for an operational question, for example to check that a webhook arrived. ```sql SELECT id, source, idempotency_key, event_type, state, created_at, processed_at FROM inbox WHERE source = 'stripe' ORDER BY created_at DESC LIMIT 20; ``` ```sql SELECT TOP 20 id, source, idempotency_key, event_type, state, created_at, processed_at FROM inbox WHERE source = N'stripe' ORDER BY created_at DESC; ```