Use Time-to-Live for Messages and Memories
Messages and memories can remain searchable after the conversation that created them ends. Time-to-live lets applications automatically expire records after a defined period, for example to meet compliance requirements, remove information that is likely outdated, or save storage space.
This guide shows how to configure record expiration for Oracle DB-backed messages and memories. It also explains purge jobs and per-record time-to-live overrides.
Oracle Agent Memory applies time-to-live in two layers:
- Schema-level retention defaults come from
MemoryRetentionConfig. Omittedttl_daysvalues on new writes useMemoryRetentionConfig.default_ttl_days. - Per-record
ttl_daysandttl_anchorvalues let one message or memory expire sooner, later, or from a different anchor time than the schema default.
When you choose a per-record anchor, use TimeToLiveAnchor.CREATED_AT to
count from when Oracle stores the row, or TimeToLiveAnchor.TIMESTAMP to
count from the record’s event timestamp instead.
Note: Use time-to-live when records should remain available for a defined period and then expire automatically. For example, an application might retain support details for 30 days or temporary task information for one week.
The following retention rules apply:
- Omitting
ttl_dayson a new write uses the schema default. - Passing
ttl_days=Noneusesmax_ttl_dayswhen a maximum is configured, or stores a non-expiring row when no maximum is configured. - Values above
max_ttl_daysare clamped to that maximum with a warning. - Update APIs preserve the current expiration unless
ttl_daysorttl_anchoris provided.
Hint: For package setup, see Get Started with Agent Memory. If you need a local Oracle database for this example, follow Run Oracle AI Database Locally.
Configure Schema-Level Retention Defaults
Create an OracleAgentMemory client with schema_policy=SchemaPolicy.CREATE_IF_NECESSARY
when you want the SDK to create or upgrade the managed Oracle schema and
persist a retention policy alongside it.
import oracledb
from oracleagentmemory.apis import TimeToLiveAnchor
from oracleagentmemory.core import (
MemoryExtractionConfig,
MemoryRetentionConfig,
OracleAgentMemory,
SchemaPolicy,
)
from oracleagentmemory.core.embedders.embedder import Embedder
embedder = Embedder(model="YOUR_EMBEDDING_MODEL")
db_pool = oracledb.SessionPool(
user="YOUR DB USER",
password="YOUR DB PASSWORD",
dsn="YOUR DB CONNECT STRING",
)
memory = OracleAgentMemory(
connection=db_pool,
embedder=embedder,
schema_policy=SchemaPolicy.CREATE_IF_NECESSARY,
memory_extraction_config=MemoryExtractionConfig(extract_memories=False),
memory_retention_config=MemoryRetentionConfig(
default_ttl_days=30,
max_ttl_days=90,
),
)
In this configuration:
- new writes that omit
ttl_daysdefault to30days - explicit
ttl_daysvalues above90days are clamped with a warning - explicit
ttl_days=Noneresolves to90days becausemax_ttl_daysis set
API Reference: OracleAgentMemory
Add Messages and Memories with Time-to-Live
Use thread writes to rely on the schema default TTL for some records while setting a different TTL for others.
from datetime import datetime, timezone
ttl_thread = memory.create_thread(
thread_id="ttl_demo_thread",
user_id="user_123",
)
message_ids = ttl_thread.add_messages(
[
{
"id": "msg-ttl-1",
"role": "user",
"content": (
"I opened ticket 1042 yesterday because the laptop battery failed."
),
"timestamp": "2026-04-01T09:00:00Z",
},
{
"id": "msg-ttl-2",
"role": "assistant",
"content": (
"I will keep ticket 1042 active and send a replacement checklist."
),
"timestamp": "2026-04-01T09:01:00Z",
},
]
)
timestamp = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
#for instance, 2026-04-01T09:00:00Z
backfilled_memory_id = ttl_thread.add_memory(
"Ticket 1042 battery-failure report was filed on 2026-04-01.",
memory_id="mem-ttl-backfill",
timestamp=timestamp,
ttl_days=90,
ttl_anchor=TimeToLiveAnchor.TIMESTAMP,
)
short_lived_memory_id = ttl_thread.add_memory(
"Replacement checklist should be revisited within one week.",
memory_id="mem-ttl-short",
ttl_days=7,
)
print(message_ids)
print(backfilled_memory_id)
print(short_lived_memory_id)
#['msg-ttl-1', 'msg-ttl-2']
#mem-ttl-backfill
#mem-ttl-short
In this example:
add_messages()omitsttl_days, so both messages use the schema default of30daysmem-ttl-backfillexpires90days after the stored event timestamp because it usesTimeToLiveAnchor.TIMESTAMPmem-ttl-shortoverrides the default and expires after7days
API Reference: OracleThread
Refresh Time-to-Live on Existing Records
Use update_message() or update_memory() to refresh an existing
expiration without replacing the stored content.
ttl_thread.update_message("msg-ttl-1", ttl_days=14)
ttl_thread.update_memory(
"mem-ttl-backfill",
ttl_days=60,
ttl_anchor=TimeToLiveAnchor.TIMESTAMP,
)
These calls keep the stored content and metadata in place while recomputing the
expiration window. Remember that updates preserve the current expiration unless
you pass ttl_days or ttl_anchor.
API Reference: OracleThread
Ensure the Managed Purge Job Exists
When Oracle Agent Memory creates or upgrades its managed Oracle schema, it also
creates a daily DBMS_SCHEDULER job that deletes expired message and memory
rows and their retrieval chunks. The job purges rows in batches instead of
issuing one large delete, commits between batches, and captures one reference
timestamp up front so a single run uses one consistent expiration cutoff.
The scheduler definition also sets schedule_limit to one day so a run that
starts too late can be skipped instead of running arbitrarily late. The job
body separately stops taking new batches after one day from the run start time.
That runtime limit is checked between batches, so a batch already in progress
is allowed to finish and commit. At the end of a run, the job writes a short
DBMS_OUTPUT summary that includes whether the runtime limit was reached and
how many rows were deleted by category.
When SchemaPolicy.CREATE_IF_NECESSARY needs to create that job but the
schema user lacks CREATE JOB, setup completes with a warning. Expired
records stay hidden from reads and search, but they are not physically purged
until a privileged user creates the job.
If you use table_name_prefix, apply the same prefix to the job and table
names below. The default managed job name is PURGE_EXPIRED_RECORDS_J.
Tip: Use the following DBA options when the schema owner does not have CREATE JOB.
Grant Scheduler Job Privileges
GRANT CREATE JOB TO app_schema;
-- Run OracleAgentMemory schema setup as app_schema.
REVOKE CREATE JOB FROM app_schema;
Create the Purge Job Manually
Replace APP_SCHEMA with the managed schema owner and adjust object
names if a table-name prefix is configured. The PL/SQL block below is
intentionally compact so it stays within Oracle Scheduler’s
job_action length limit even when prefixed object names are long:
BEGIN
DBMS_SCHEDULER.CREATE_JOB(
job_name => 'APP_SCHEMA.PURGE_EXPIRED_RECORDS_J',
job_type => 'PLSQL_BLOCK',
job_action => q'[
DECLARE
bs CONSTANT PLS_INTEGER := 1000;
n PLS_INTEGER;
mc PLS_INTEGER := 0;
xc PLS_INTEGER := 0;
mr PLS_INTEGER := 0;
xr PLS_INTEGER := 0;
tl PLS_INTEGER := 0;
rt TIMESTAMP(6) WITH TIME ZONE := SYSTIMESTAMP;
dl TIMESTAMP(6) WITH TIME ZONE := rt + INTERVAL '1 00:00:00' DAY TO SECOND;
BEGIN
LOOP
IF SYSTIMESTAMP >= dl THEN
tl := 1;
EXIT;
END IF;
DELETE FROM APP_SCHEMA.RECORD_CHUNKS c
WHERE c.rowid IN (
SELECT rid
FROM (
SELECT c.rowid AS rid
FROM APP_SCHEMA.RECORD_CHUNKS c
WHERE c.source_record_type = 'message'
AND EXISTS (
SELECT 1
FROM APP_SCHEMA.MESSAGE m
WHERE m.record_id = c.source_id
AND m.expires_at IS NOT NULL
AND m.expires_at <= rt
)
FETCH FIRST bs ROWS ONLY
)
);
n := SQL%ROWCOUNT;
mc := mc + n;
EXIT WHEN n = 0;
COMMIT;
END LOOP;
LOOP
IF SYSTIMESTAMP >= dl THEN
tl := 1;
EXIT;
END IF;
DELETE FROM APP_SCHEMA.RECORD_CHUNKS c
WHERE c.rowid IN (
SELECT rid
FROM (
SELECT c.rowid AS rid
FROM APP_SCHEMA.RECORD_CHUNKS c
WHERE c.source_record_type IN ('fact', 'guideline', 'memory', 'preference')
AND EXISTS (
SELECT 1
FROM APP_SCHEMA.MEMORY m
WHERE m.record_id = c.source_id
AND m.memory_type = c.source_record_type
AND m.expires_at IS NOT NULL
AND m.expires_at <= rt
)
FETCH FIRST bs ROWS ONLY
)
);
n := SQL%ROWCOUNT;
xc := xc + n;
EXIT WHEN n = 0;
COMMIT;
END LOOP;
LOOP
IF SYSTIMESTAMP >= dl THEN
tl := 1;
EXIT;
END IF;
DELETE FROM APP_SCHEMA.MESSAGE
WHERE rowid IN (
SELECT rid
FROM (
SELECT rowid AS rid
FROM APP_SCHEMA.MESSAGE
WHERE expires_at IS NOT NULL
AND expires_at <= rt
FETCH FIRST bs ROWS ONLY
)
);
n := SQL%ROWCOUNT;
mr := mr + n;
EXIT WHEN n = 0;
COMMIT;
END LOOP;
LOOP
IF SYSTIMESTAMP >= dl THEN
tl := 1;
EXIT;
END IF;
DELETE FROM APP_SCHEMA.MEMORY
WHERE rowid IN (
SELECT rid
FROM (
SELECT rowid AS rid
FROM APP_SCHEMA.MEMORY
WHERE expires_at IS NOT NULL
AND expires_at <= rt
FETCH FIRST bs ROWS ONLY
)
);
n := SQL%ROWCOUNT;
xr := xr + n;
EXIT WHEN n = 0;
COMMIT;
END LOOP;
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge reference_time='
|| TO_CHAR(rt, 'YYYY-MM-DD"T"HH24:MI:SS.FF3TZH:TZM')
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge run_deadline='
|| TO_CHAR(dl, 'YYYY-MM-DD"T"HH24:MI:SS.FF3TZH:TZM')
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge runtime_limit_reached='
|| CASE WHEN tl = 1 THEN 'true' ELSE 'false' END
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge deleted message chunk rows='
|| TO_CHAR(mc)
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge deleted fact/guideline/memory/preference chunk rows='
|| TO_CHAR(xc)
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge deleted message rows='
|| TO_CHAR(mr)
);
DBMS_OUTPUT.PUT_LINE(
'OracleAgentMemory purge deleted fact/guideline/memory/preference rows='
|| TO_CHAR(xr)
);
END;
]',
start_date => SYSTIMESTAMP,
repeat_interval => 'FREQ=DAILY;INTERVAL=1',
enabled => FALSE,
auto_drop => FALSE,
comments => 'OracleAgentMemory expired-record purge'
);
DBMS_SCHEDULER.SET_ATTRIBUTE(
name => 'APP_SCHEMA.PURGE_EXPIRED_RECORDS_J',
attribute => 'logging_level',
value => DBMS_SCHEDULER.LOGGING_RUNS
);
DBMS_SCHEDULER.SET_ATTRIBUTE(
name => 'APP_SCHEMA.PURGE_EXPIRED_RECORDS_J',
attribute => 'store_output',
value => TRUE
);
DBMS_SCHEDULER.SET_ATTRIBUTE(
name => 'APP_SCHEMA.PURGE_EXPIRED_RECORDS_J',
attribute => 'schedule_limit',
value => INTERVAL '1 00:00:00' DAY TO SECOND
);
DBMS_SCHEDULER.ENABLE('APP_SCHEMA.PURGE_EXPIRED_RECORDS_J');
END;
/
It is useful to confirm the scheduler definition and inspect recent run
history. Replace APP_SCHEMA if needed and apply the configured
table-name prefix to the job name when your deployment uses one.
Check that the managed purge job exists and kept the expected inspection settings:
SELECT owner,
job_name,
enabled,
state,
repeat_interval,
schedule_limit,
logging_level,
store_output,
start_date,
last_start_date,
next_run_date
FROM all_scheduler_jobs
WHERE owner = 'APP_SCHEMA'
AND job_name = 'PURGE_EXPIRED_RECORDS_J';
Check recent runs when you need to confirm that purge executions are happening and finishing successfully:
SELECT log_date,
status,
run_duration,
output,
additional_info
FROM all_scheduler_job_run_details
WHERE owner = 'APP_SCHEMA'
AND job_name = 'PURGE_EXPIRED_RECORDS_J'
ORDER BY log_date DESC;
Run the job once manually if you want to validate the installation immediately:
BEGIN
DBMS_SCHEDULER.RUN_JOB(
job_name => 'APP_SCHEMA.PURGE_EXPIRED_RECORDS_J',
use_current_session => TRUE
);
END;
/
Conclusion
In this guide we learned how schema-level retention defaults, per-record
ttl_days values, and TimeToLiveAnchor work together, how the managed
purge job removes expired rows, and how to refresh existing expirations from
Python.
For more information about filtering records by metadata, see Use Metadata and Metadata Filtering.
Full Code
The following code combines the examples in this guide.
#Copyright © 2026 Oracle and/or its affiliates.
#This software is under the Apache License 2.0
#(LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0) or Universal Permissive License
#(UPL) 1.0 (LICENSE-UPL or https://oss.oracle.com/licenses/upl), at your option.
#Oracle Agent Memory Code Example - Use Time-to-Live for Messages and Memories
#-----------------------------------------------------------------------------
##Create a retention aware client
from datetime import datetime, timezone
import oracledb
from oracleagentmemory.apis import TimeToLiveAnchor
from oracleagentmemory.core import (
MemoryExtractionConfig,
MemoryRetentionConfig,
OracleAgentMemory,
SchemaPolicy,
)
from oracleagentmemory.core.embedders.embedder import Embedder
embedder = Embedder(model="YOUR_EMBEDDING_MODEL")
db_pool = oracledb.SessionPool(
user="YOUR DB USER",
password="YOUR DB PASSWORD",
dsn="YOUR DB CONNECT STRING",
)
memory = OracleAgentMemory(
connection=db_pool,
embedder=embedder,
schema_policy=SchemaPolicy.CREATE_IF_NECESSARY,
memory_extraction_config=MemoryExtractionConfig(extract_memories=False),
memory_retention_config=MemoryRetentionConfig(
default_ttl_days=30,
max_ttl_days=90,
),
)
##Add messages and memories with time to live
ttl_thread = memory.create_thread(
thread_id="ttl_demo_thread",
user_id="user_123",
)
message_ids = ttl_thread.add_messages(
[
{
"id": "msg-ttl-1",
"role": "user",
"content": (
"I opened ticket 1042 yesterday because the laptop battery failed."
),
"timestamp": "2026-04-01T09:00:00Z",
},
{
"id": "msg-ttl-2",
"role": "assistant",
"content": (
"I will keep ticket 1042 active and send a replacement checklist."
),
"timestamp": "2026-04-01T09:01:00Z",
},
]
)
timestamp = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
#for instance, 2026-04-01T09:00:00Z
backfilled_memory_id = ttl_thread.add_memory(
"Ticket 1042 battery-failure report was filed on 2026-04-01.",
memory_id="mem-ttl-backfill",
timestamp=timestamp,
ttl_days=90,
ttl_anchor=TimeToLiveAnchor.TIMESTAMP,
)
short_lived_memory_id = ttl_thread.add_memory(
"Replacement checklist should be revisited within one week.",
memory_id="mem-ttl-short",
ttl_days=7,
)
print(message_ids)
print(backfilled_memory_id)
print(short_lived_memory_id)
#['msg-ttl-1', 'msg-ttl-2']
#mem-ttl-backfill
#mem-ttl-short
##Refresh time to live on existing records
ttl_thread.update_message("msg-ttl-1", ttl_days=14)
ttl_thread.update_memory(
"mem-ttl-backfill",
ttl_days=60,
ttl_anchor=TimeToLiveAnchor.TIMESTAMP,
)