# Metadata properties

**URL:** <https://forum.weaviate.io/t/metadata-properties/7572>\
**Category:** Support\
**Created:** [November 14, 2024, 1:41pm UTC](https://forum.weaviate.io/t/metadata-properties/7572 "2024-11-14T13:41:07Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![2020ashish](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/2020ashish/32/797_2.png) [@2020ashish](https://forum.weaviate.io/u/2020ashish)\
**Post date:** [November 14, 2024, 1:41pm UTC](https://forum.weaviate.io/t/metadata-properties/7572/1 "2024-11-14T13:41:07Z")

</div>

### Description

What is behavior of creation time and last\_update time in metadata.  
Why creation\_time is always updating.

```auto

import weaviate.classes.config as wcc
import weaviate.classes as wvc

client.collections.create(
    name="Test_time",
    vectorizer_config=wcc.Configure.Vectorizer.text2vec_transformers(),
    inverted_index_config=wcc.Configure.inverted_index(
        index_timestamps = True
    ),
    properties=[
        wcc.Property(
            name="question",
            data_type=wcc.DataType.TEXT,
            tokenization=wcc.Tokenization.WORD,
        ),
        wcc.Property(
            name="answer",
            data_type=wcc.DataType.TEXT,
            tokenization=wcc.Tokenization.FIELD,
        )
    ],
)

```

```auto
dddd = [
    
    {"question": "What is 2 + 2?", "answer": "41"},
    {"question": "What is the largest ocean?", "answer": "Pacific Ocea1n"},
   ]
from weaviate.util import generate_uuid5
import numpy as np
count=0
with client.batch.dynamic() as batch:
    for idd in dddd:
        count+=1
        batch.add_object(
            properties=idd,
            vector=np.random.rand(1536),
            collection="Test_time",
            uuid=generate_uuid5(f"test_time-id-{count}")
        )
if client.batch.failed_objects:
    print("Failed Objects: ", client.batch.failed_objects)

```

If I again use add\_object with update data like  
dddd = [

```
{"question": "What is 2 + 2?", "answer": "4"},
{"question": "What is the largest ocean?", "answer": "Pacific Ocean"},

```

]  
Why creation time gets updated ?

### Server Setup Information

- Weaviate Server Version:
- Deployment Method: 
- Multi Node? Number of Running Nodes:
- Client Language and Version:
- Multitenancy?:

### Any additional Information

---

<div class="post-metadata">

**Author:** ![Shahin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shahin/32/7944_2.png) [@Shahin](https://forum.weaviate.io/u/Shahin)\
**Post date:** [November 15, 2024, 10:09am UTC](https://forum.weaviate.io/t/metadata-properties/7572/2 "2024-11-15T10:09:58Z")

</div>

Good morning @2020ashish, Happy Friday! 🤗

In Weaviate, each data object has two primary timestamps:

• **creationTimeUnix** : The timestamp when the object was initially created.

• **lastUpdateTimeUnix** : The timestamp of the object’s most recent update.

Both timestamps will remain identical until the object is explicitly updated using the update\_object method, which only modifies the lastUpdateTimeUnix while keeping the creationTimeUnix intact.

However, in **batch operations with** add\_object, if the same UUID is provided, Weaviate will **overwrite the existing object** , treating it as a new insertion. If the UUID is different, no overwriting occurs.

Does that make sense?

---

<div class="post-metadata">

**Author:** ![2020ashish](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/2020ashish/32/797_2.png) [@2020ashish](https://forum.weaviate.io/u/2020ashish)\
**Post date:** [November 15, 2024, 10:29am UTC](https://forum.weaviate.io/t/metadata-properties/7572/3 "2024-11-15T10:29:17Z")

</div>

Thanks @Shahin  
Curretly facing huge read/write operation in mentioned case.  
can you help me optimize my code [I am getting hnsw\_vector\_cache\_prefill frequently - #5 by 2020ashish](https://forum.weaviate.io/t/i-am-getting-hnsw-vector-cache-prefill-frequently/7501/5)