[Bug] Subgraph indexing very slow when block handler is used even if block handler's start block has not reached

Bug report

When this subgraph is deployed with block handler, subgraph is indexing very slow even if block handler's start block has not reached. When the data source with block handler is removed, subgraph is syncing much faster.

Deployment ID without block handler - QmaTYtcFZUobuUqdZL8mjvMhYUD5qE9egsMJQHsJkpMV3z
Deployment ID with block handler - QmQBNYbUVLvLVYEtc7zRRWJNMwkETVfn73VT2z2c7eden4

Relevant log output

No response

IPFS hash

No response

Subgraph name or link to explorer

No response

Some information to help us out

• Tick this box if this bug is caused by a regression found in the latest release.
• Tick this box if this bug is specific to the hosted service.
• I have searched the issue tracker to make sure this issue is not a duplicate.

OS information

None

まず、block handler なしの deployment QmaTYtcFZUobuUqdZL8mjvMhYUD5qE9egsMJQHsJkpMV3z と、block handler ありの QmQBNYbUVLvLVYEtc7zRRWJNMwkETVfn73VT2z2c7eden のインデックス作成動作を比較します。block handler のデータソースが、設定された開始ブロックより前にどのように処理されるかを追跡し、そのブロックに到達するまではインデックス作成速度に影響がないことを確認します。