Plexara
Spreadsheets as Tables
501 - The last mile of data is a spreadsheet
The join was never the expensive part of using an outside file. Loading it was, and loading was staffed: a ticket for the table, an engineer for the load, an integration platform somebody had to keep. A chat agent does not close that gap on its own, because a large file does not fit its context and the scripts it writes vanish with the session. This lesson sets out the gap, the registration model that closes it (a table over the file where it sits, nothing copied), and the size rule for when a file needs no table at all.
502 - Uploading a file and registering it as a table
The mechanics. Upload a file to the resource library with a description search will match, export a spreadsheet as UTF-8 CSV first, register it from the file’s own page or with one sentence to the agent, and read what comes back: the qualified name, the columns, and a sample statement with the cast. Then the Scratch Tables page, where every registration is listed with its state, and the three things a file can be refused for, with the repair that writes a corrected version through the file’s own history.
503 - Teaching the agent what the file means
A header row says what the columns are called, not what they mean. This lesson is the five minutes after registration: telling the agent the units, the grain, the effective dating, the join key, and what a missing row means; letting it capture that as memory; promoting the capture to a knowledge page so every teammate’s agent recalls it; and recording the first successful join as a reusable query. Registering publishes the data. This is how you publish the meaning.
504 - Joining, visualizing, and sharing
The join, with the cast every registered column needs, run against a real supplier quote and a month of sales: cost change by category, the SKUs whose margin falls under a threshold at the current price, and the SKUs the sheet does not cover. The result becomes a dashboard asset with provenance, shared with the people who need it. The lesson closes with the choice between querying a registered table and having a dashboard reference the file directly, which re-reads it on every open.
505 - Next month’s file
The new sheet arrives. Replacing the file’s content writes a new revision, and the registered table keeps reading the old one until it is registered again under the same name; the Scratch Tables page says so. This lesson covers the two cases that look alike and behave differently, moving the table forward, unregistering, what deleting the file does, saving the monthly procedure as a prompt, and the point at which a monthly file needs more than a join, which is where the 600 series begins.