Tables
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A table is where tabular data is stored on Redivis. A table can be thought of as a grid made up of variables (columns) and rows (records). You'll see tables:
On the Tables tab of datasets
On table nodes in a workflow
Every table has a table viewer where you can explore the data, given you have appropriate access. There are three tabs where you can view the data and interact with it in different ways:
Variables view (requires metadata access)
Cells view (requires data access)
Query view (requires data access)
Field
Notes
Name
The table's name. If in a dataset, must be unique across all tables for that version of the dataset. If in a workflow, must be unique across all tables currently in the workflow.
Description
Optional. A free-form description of the table's contents. May not exceed 5000 characters.
Variable count
Total number of variables in the table.
Row count
Total number of rows, or records, in the table.
Size
Total size of the table, in bytes.
Entity
Optional. Documents the concept that one record in this table represents. For example, the table's entity might represent a unique patient, or a specific hospitalization, or a prescription.
Temporal range
Optional. The range of time that this table covers. This can either be set manually, or calculated from the min/max of a particular variable.
Sample
If this table is sampled, you will see a marker for whether you are looking at the full dataset or the 1% sample. To interact with sampled tables, add the dataset to a workflow.
The Variables tab provides a searchable list of the table's variables. In order to view this tab, you will need metadata access to the corresponding table.
Clicking any row will display the variable's statistics panel, which shows some common summary statistics calculated from the variable's data.
The Cells tab allows you to quickly preview and explore the table's data as a grid, regardless of the table's size. In order to view this tab, you will need data access to the corresponding table.
Clicking any the header or cells in any column will display the variable's summary statistics. You can also right click a cell to filter by a specific value, or sort on that variable.
For any Geography type variables, you can hover on the cell or click to see a preview.
The order of records within a table is arbitrary and non-deterministic, unless the table is the result of a transform or query that specifies an order clause.
This behavior allows for the performance and scaling characteristics of tabular data on Redivis, and is typical for relational databases and other tabular data stores.
If the order of records is considered to be part of the "data" in your table, you should create an additional "record number" variable that can be sorted on. Alternatively, you can upload your source files as unstructured data, in which case an exact copy of the original file will be stored.
Workflow transforms provide the most robust and reproducible mechanism for querying tables on Redivis. However, you can execute SQL queries directly on a table for when you want to perform a quick, one-off analysis. In order to perform a query, you will need data access to the corresponding table.
The Query tab on a table contains a SQL editor with scaffolding to reference that table. The query syntax follows the same rules as the transform SQL query syntax. Additionally query results may not exceed 10GB – if you need to materialize larger results, use a transform for your query.
Choose one of the templates or type your own SQL query, and click the Run button to see the results. You can select any column in the query results to view the summary statistics for that column.
If you update the query after execution, it will become "stale" (marked in yellow), which is a reminder that the results no longer match the query you are typing. The previous results will still be shown to help inform the new query you are writing.
Accessibility note for keyboard navigation: When you open the query tab, your cursor will be focused on the query editor. To navigate away using the keyboard, first press Escape, then press Tab to focus with other non-editor elements.
If calculated from a variable, that variable must have date, dateTime, or integer. If the variable is an integer, its values will be assumed to represent a year and must be in the range [0, 9999].
