Confirming the use of SummaryIndex for summarizing pdf ...

At a glance

The community member has around 1000 PDF documents and wants to create a summary for each document. They are unsure whether to use the SummaryIndex or the DocumentSummaryIndex from the LlamaIndex library. The comments suggest that the DocumentSummaryIndex is better suited for this task, as it generates a summary for each document in a one-time effort during the index building process, whereas the SummaryIndex iterates through each node and passes it to the language model, which can be more time-consuming.

The community member also has questions about the implementation details, such as whether to create a summary document and add it to a DuckDB vector store, or to create the index and attach it to the DuckDB vector store. They also want to know how to print the summaries generated by the DocumentSummaryIndex and whether they should loop through the documents one by one or dump all of them and then print the individual summaries.

The comments provide explanations about the differences between the SummaryIndex and the DocumentSummaryIndex, clarifying that the SummaryIndex does not actually summarize the nodes, but rather iterates through them to form the final answer, which can be more costly. The community members also confirm their understanding of how the SummaryIndex works in terms of passing each node, the query, and the previous

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JJatin.K

I have around 1000 pdf documents (slides, scientific publications etc.). I want to create summary of each document. As per my understanding i need to use SummaryIndex(https://docs.llamaindex.ai/en/stable/api_reference/indices/summary/) and not DocumentSummaryIndex(https://docs.llamaindex.ai/en/stable/examples/index_structs/doc_summary/DocSummary/). Can someone confirm? And any tips before i setup the pipeline.

12 comments

WWhiteFang_Jr

If you need summary of each document then you need to use DocumentSummaryIndex.

SummaryIndex basically pulls all the nodes and iterate over them one by one to form the final answer. This would increase the time taken to respond.

Whereas DocumentSummaryIndex is a one time effort that comes while building your index. Each Document object goes through LLM and and generates a summary against it.

JJatin.K

1) It's only a one time activity. Since I want to generate a document that will contain summary of all the papers (1st column document name and 2nd column document summary) so I am not worry about time taken to response. Ultimatey I want to append this summary document into the persisting DuckDB vector store. 2) Which one is better, creating summary document and adding it into persisting DuckDB vector store or create the index and attach this new index to persisting DuckDB vector store file? 3) How to print summary generated by DocumentSummaryIndex for a given document and shall i loop through all documents one by one or dump all of them and then print individual summary to a payload file while going through each doc_ID.

JJatin.K

Can you explain more about SummaryIndex as it's documentation is not detail rich (https://docs.llamaindex.ai/en/stable/api_reference/indices/summary/); like when you say 'pulls all the nodes', how do it does that, based upon summary or some filter/prompt tokens?.

JJatin.K

As per my understanding, there is no implicit LLM powered summary generation step involved (like backend summary generation step in DocumentSummaryIndex) despite the word Summary in it's name SummaryIndex, correct? If correct, just curious, why to name it SummaryIndex?

JJatin.K

Does both method insures that all the nodes belonging to a document are considered while summarizing? or it may be a hit or miss in SummaryIndex since its summarization will be solely based upon prompt instructions and there is no paramteric control to force the system to consider all the nodes blonging to a document while generating summary?

WWhiteFang_Jr

So in summary index, once you ask a query, it iterates through each node that you have and pass it to the LLM along with query and previous context to form a updated answer. This goes on until all the nodes are consumed .
This is a costly approach as you will iterate over all the nodes for every query.

Whereas in DocumentSummaryIndex Before chunking documents into Nodes , Summary is created over the whole Document and it is attached to the chunked nodes of that document.

This is one time cost

JJatin.K

correct me if I'm wrong: If i load docA and it got split into nodeA, nodeB and nodeC(a sequence respecting the source document's content's sequence); to answer a query, it will first pass the nodeA + query + previous context(if any) to the LLM and get answerA; then it will pass nodeB + query + previous context(function of answerA) to the LLM and get answerB; finally it will pass nodeC + query + previous context(function of answerA+answerB) to get answerC; and that answerC will be displayed to the user as a answer to the query. Am i correct?

WWhiteFang_Jr

Yes

JJatin.K

so it's called SummaryIndex because it is touching all the nodes and not because it's summarizing all the nodes on backend like DocumentSummaryIndex does? right?

WWhiteFang_Jr

Yes

JJatin.K

I am coming across following error for 1600 document objects

JJatin.K

my code snippet

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Confirming the use of SummaryIndex for summarizing pdf documents