Running Data Systems
Operate, change, protect and retire a data system, then assemble the complete case study.
Permissions, Secrets and Tenant Boundaries
Finding a record and being allowed to read it are different questions. A correct query can return information to the wrong person. This chapter adds an…
4,266 words/19 min read48Retention, Deletion and Data Lineage
Information has a useful lifetime. Keeping it forever can create unnecessary exposure; deleting it carelessly can destroy evidence, break references or…
4,076 words/18 min read49Schema Changes Without Surprises
A schema change alters the agreement between stored records and the programs using them. The challenge is not merely to make a new table definition…
3,923 words/17 min read50Observability, Capacity and Cost
A running system produces signals about its behaviour. Useful observability connects those signals to questions: Are users completing their work? Where…
3,922 words/17 min read51Capstone: From One Shop to a Multi-Branch Service
We began with a person recording a sale. We can now name the contracts, representations, queries, transactions, copies and operational responsibilities…
4,379 words/19 min read52The Reference Desk: Glossary and Diagnostic Guides
This chapter is a place to return when a term, query or failure needs a precise next step. It is not a substitute for the explanations earlier in the…
4,323 words/19 min read