> Copy your database in a second, and look inside it from the studio. # Branches and browsing Your project has **one database**. What it has many of is **branches** — copies of that database, each with its own connection string. The studio shows the branches, the tables on each, and the rows in each table. You can change a value in place. ## Branches A branch is a copy-on-write clone. Creating one takes about a second **whatever the size of the parent**, because nothing is copied: the branch points at the same data and diverges only as it is written to. ``` production your database ├── staging everything production had at 14:32, going its own way since └── preview/pr-42 ``` That is a different thing from an empty second database, and a more useful one. A preview environment wants *production's rows as they are now*, not an empty schema. A migration rehearsal wants the data that will break it. **Each branch has its own compute and its own host.** The connection string for `staging` is not production's with a word changed — it is a different machine. Writes on one never reach the other; the copy was taken once, at the moment you made it. **You pay for what diverges**, plus the compute each branch uses while it is awake. A branch nobody queries costs almost nothing, and one that has drifted a gigabyte from its parent costs that gigabyte. Ten branches per project. Ask if you need more — it is a bound on runaway CI jobs rather than on cost. **A branch never expires on its own.** The engine underneath supports branches with a time to live, and we do not use it: a branch you made to hold a copy of production before a migration is still there next week, and next month. Branches go when somebody deletes them. ### Deleting a branch Type its name to confirm. The branch and its compute go; **anything written to it since the copy was taken is lost**, and its parent is untouched. Two branches cannot be deleted: - **production**, which is the database itself. Deleting the project removes it, and that is reversible for 30 days. - **any branch with branches of its own** — delete those first. A copy cannot outlive the thing it was copied from. ## Browsing Open a branch to see its tables: names, estimated row counts, and size. Open a table to see its rows, fifty at a time, ordered by primary key so that page two is the same page two on the next click. It is not a replacement for a SQL client. There is no query box, no schema editor, no import. It is for the thing you actually open a client for most often: *what is in this table right now, and can I fix that one wrong row.* The list says *about* n rows because it is Postgres's own estimate — an exact count means scanning the table, and doing that for every table to draw a list would wake the compute and hold it. Open a table and the count at the bottom is exact. ## Editing a value Click a value, change it, save. One cell, one row, one `update`. **A table needs a primary key to be editable.** Without one there is no way to name a single row — `where email = …` could match four — so those tables are shown read-only rather than edited hopefully. Adding a primary key makes them editable. Primary key columns are not editable here either. Changing a key moves a row rather than edits it, and doing that from a grid is how a foreign key ends up pointing at nothing. An empty field means `null` where the column allows it, and is refused where it does not. `null` and an empty string are different values and the studio shows them differently. ## What it means that we can see it Everywhere else, your database is yours alone: your application connects directly, and nothing of ours is on that path. **This page is the exception.** To draw a table for you, our server connects to your branch. So, plainly: - **It uses your credential**, the same connection string you have. The studio can do nothing in your database that you cannot do yourself. - **It happens only while somebody has the page open.** There is no background job reading your data, and nothing is copied to our side — each page is a query, and when the tab closes there is nothing left. - **Only your schemas.** Postgres's own catalogs are refused rather than listed, including the one that holds role password hashes. - **There is one write**, a single-cell update addressed by primary key. No statement in the studio can affect a row that was not named. - **Only owners and admins can change data.** Members see the same tables and cannot edit them. If that is not a trade you want to make, do not use this page — everything else about your database works the same either way, and nothing here is required.