Google TSE · Storage & Databases

Listen while you move

12 episodes (E1–E8 study + E9–E12 daily repetition). Play the MP3 (works in the car / Files app) or tap Read aloud to use your phone's voice. After each episode, pause and say the key line out loud — that repetition is the study. New: MOCK_PROMPTS.md (Gemini Live S1–S10) · HANDOFF_NOTE.md (Day 8 drill) · see STUDY_PLAN_V2.md for the persona-improved daily repetition stack.

Tap the card to flip · Say your answer out loud before flipping

Scenario drill (6–8 min each)

Pick a scenario. Start the timer. Work the 4 steps out loud, checking each off. Only then open the model outline.

Code drills — narrate before you edit

Shared-doc round: clarifying questions + test cases, Big-O, malformed input, tradeoffs. The narration is what's scored.

Drill 1 · Log parser — top 5 errors/min + p50/p95/p99

import re, collections
pat = re.compile(r'(\d{4}-\d{2}-\d{2}T\d{2}:\d{2}):\d{2}.*?(ERROR|WARN):(\w+).*?latency=(\d+)ms')
buckets = collections.defaultdict(list)
errors  = collections.defaultdict(collections.Counter)
for line in open('db.log'):
    m = pat.search(line)
    if not m: continue  # malformed: skip + count
    minute, level, code, lat = m.group(1), m.group(2), m.group(3), int(m.group(4))
    buckets[minute].append(lat)
    if level == 'ERROR': errors[minute][code] += 1
for minute in sorted(buckets):
    lats = sorted(buckets[minute])
    pct = lambda p: lats[min(len(lats)-1, int(len(lats)*p))]
    print(minute, errors[minute].most_common(5), pct(.5), pct(.95), pct(.99))

Talk track: regex → bucket by minute → Counter → sort for percentiles. O(n log n). Then say the BigQuery version: TIMESTAMP_TRUNC(ts, MINUTE) + GROUP BY + window functions.

Drill 2 · Health check — connections + replica lag

SELECT count(*) FROM pg_stat_activity;
SELECT EXTRACT(EPOCH FROM (now() - pg_last_xact_replay_timestamp()));

Alert after 3 consecutive breaches (no flapping). Backoff with jitter — never hammer a sick DB. Run as cron / Cloud Run / Monitoring alert.

Drill 3 · Auditor — flag public buckets & no-backup instances

gcloud storage buckets list --format=json   # iamConfiguration.publicAccessPrevention
gcloud sql instances list --format=json     # backupConfiguration.enabled / PITR

Parse defensively (.get with defaults). This is the JD's “build investigation tools” in Python.

Drill 4 · Buggy client — name all 5 before editing

Cheat sheet

Decision matrix — 30-second answers

Checklists

Can't connect (Cloud SQL): IAM → PSA/PSC → Proxy/connector → SSL → limits → pool math.
Disappearing objects: lifecycle → retention/Bucket Lock → soft delete → versioning → Data Access audit log.
Hotspot: Key Visualizer → leading key field → UUID / bit-reversed / hash prefix / promote high-cardinality field.
GKE→DB: DNS → sidecar → Workload Identity → DB limit → network policy. Capture: no SYN = local/policy · SYN+RST = refused · SYN+retransmits = path drop · TLS alert = SSL mode.

Gap line — never bluff

Resources (official first)

TSE Prep Guide · Database Engineer Learning Path · Google Cloud Tech (YouTube) · SRE Books (free)
Full day-by-day watch/read/do list: open RESOURCES.md in this folder.