<p>Pruning does not only keep the UTXO set. It also keeps the latest few hundred blocks, in order to assist with reorganizations.</p>

<p>Pruning was experimental in Bitcoin Core 0.11, and incompatible with the wallet. Since 0.12, it's a fully supported feature that works fine with the wallet.</p>

CC BY-SA 3.0
2017-10-22T17:13:45.133Z
So does pruning mean: keeping last N blocks, including necessarily all UTXOs, instead of entire blockchain?
croraf
CC BY-SA 3.0
2017-10-22T17:54:11.413Z
It means keeping (a) all UTXOs, from any time and (b) the last few blocks.
Pieter Wuille
CC BY-SA 3.0
2017-09-12T20:39:38.703Z
2017-09-12T20:39:38.703Z
Pieter Wuille
<p>In order to reduce the size of the blockchain, we can use pruning with the bitcoin core client. The description of the option says:</p>

<blockquote>
  <p>Reduce storage requirements by pruning (deleting) old blocks. This
  mode disables wallet support and is incompatible with -txindex.</p>
</blockquote>

<p>If I understand other sources explaining pruning, correctly, it will only keep unspent transaction outputs (UTXOs). This is what's stored in the LevelDB in the chainstate directory. Therefore, I would expect <strong>pruning to remove all other files</strong> (or rather all blk files) <strong>and only keep the chainstate DB</strong>. I cannot test this myself right now, hence my question.
If someone uses the pruned mode, can you confirm that it uses around 2.5 GB (size of the chainstate)?
Also, why does pruning disable the <em>wallet support</em>?</p>

<pruning>
Blockchain pruning and chainstate
Roper
# Blockchain pruning and chainstate

(Asked by: username_0 on 2017-09-12)

In order to reduce the size of the blockchain, we can use pruning with the bitcoin core client. The description of the option says:

> Reduce storage requirements by pruning (deleting) old blocks. This
> mode disables wallet support and is incompatible with -txindex.

If I understand other sources explaining pruning, correctly, it will only keep unspent transaction outputs (UTXOs). This is what's stored in the LevelDB in the chainstate directory. Therefore, I would expect **pruning to remove all other files** (or rather all blk files) **and only keep the chainstate DB**. I cannot test this myself right now, hence my question.
If someone uses the pruned mode, can you confirm that it uses around 2.5 GB (size of the chainstate)?
Also, why does pruning disable the *wallet support*?

**Tags:** pruning


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## 1 answers

### Answer by username_1 on 2017-09-12. Score: 4 | Accepted answer

Pruning does not only keep the UTXO set. It also keeps the latest few hundred blocks, in order to assist with reorganizations.

Pruning was experimental in Bitcoin Core 0.11, and incompatible with the wallet. Since 0.12, it's a fully supported feature that works fine with the wallet.

> **Comments:**
> **username_2**: So does pruning mean: keeping last N blocks, including necessarily all UTXOs, instead of entire blockchain?  
> **username_1**: It means keeping (a) all UTXOs, from any time and (b) the last few blocks.  

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