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Equation 3 · Part 2 · The Hidden Infrastructure Bill Behind Every RAG Answer

Symbol S

r(S)r(S)
SS

What this part means

index size in gigabytes.

Its job in the formula

S is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

where S is index size in gigabytes, r(S) is Pinecone’s documented read units per query as a function of that size, Q is monthly query volume, and pstorep_{\mathrm{store}} , prup_{\mathrm{ru}} , and prerankp_{\mathrm{rerank}} are the published per-unit rates given earlier.

The passage around this formula

where S is index size in gigabytes, r(S) is Pinecone’s documented read units per query as a function of that size, Q is monthly query volume, and pstorep_{\mathrm{store}} , prup_{\mathrm{ru}} , and prerankp_{\mathrm{rerank}} are the published per-unit rates given earlier. Set against it, the cost of skipping retrieval and instead inlining a fixed block of extra context on every single call is

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Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.